Abstract

We present a first-principles investigation of Ge paramagnetic centers in Ge-doped vitreous silica (v-SiO2) based on calculations of the electron paramagnetic resonance (EPR) parameters. We infer, by analyzing g-values differences with respect to our Ge-E′ configurations, that the EPR signal of the Ge(2) center may arise from Ge forward-oriented (Ge-FO) configurations, where the unpaired spin is localized at a three-fold Ge atom featuring a weak bond with a three-fold O atom, ∼ 1.9 Å long. Moreover we show that two-fold Ge atoms, i.e. the germanium lone pair centers (GLPC), under irradiation can easily convert into Ge-FO configurations consistently with experimental observations.

© 2015 Optical Society of America

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  60. The increase of the g3 value in v-GeO2 with respect to Ge-doped silica should be related to the shortening of the longest Ge-O bond in Ge-FO configurations [45].

2014 (2)

A. M. El-Sayed, M. B. Watkins, V. V. Afanas’ev, and A. L. Shluger, “Nature of intrinsic and extrinsic electron trapping in SiO2,” Phys. Rev. B 89(12), 125201 (2014).
[Crossref]

L. Giacomazzi, L. Martin-Samos, A. Boukenter, Y. Ouerdane, S. Girard, and N. Richard, “EPR parameters of E′ centers in v-SiO2 from first-principles calculations,” Phys. Rev. B 90(1), 014108 (2014).
[Crossref]

2013 (3)

R. I. Mashkovtsev, Z. Li, M. Mao, and Y. Pan, “73Ge, 17O and 29Si hyperfine interactions of the Ge E1′ center in crystalline SiO2,” J. Magn. Resonance 233, 7–16 (2013).
[Crossref]

S. Girard, J. Kuhnhenn, A. Gusarov, B. Brichard, M. Van Uffelen, Y. Ouerdane, A. Boukenter, and C. Marcandella, “Radiation Effects on Silica-Based Optical Fibers: Recent Advances and Future Challenges,” IEEE Trans. Nucl. Sci. 60(3), 2015–2036 (2013).
[Crossref]

N. Richard, L. Martin-Samos, S. Girard, A. Ruini, A. Boukenter, Y. Ouerdane, and J-P Meunier, “Oxygen deficient centers in silica: optical properties within many-body perturbation theory,” J. Phys. Condens. Matter 25(33), 335502 (2013).
[Crossref] [PubMed]

2011 (7)

M. Fehr, A. Schnegg, B. Rech, K. Lips, O. Astakhov, F. Finger, G. Pfanner, C. Freysoldt, J. Neugebauer, R. Bittl, and C. Teutloff, “Combined multifrequency EPR and DFT study of dangling bonds in a-Si:H,” Phys. Rev. B 84(24), 245203 (2011).
[Crossref]

M. Houssa, G. Pourtois, V. V. Afanas’ev, and A. Stesmans, “First-principles study of Ge dangling bonds in GeO2 and correlation with electron spin resonance at Ge/GeO2 interfaces,” Appl. Phys. Lett. 99(21), 212103 (2011).
[Crossref]

A. Alessi, S. Girard, C. Marcandella, S. Agnello, M. Cannas, A. Boukenter, and Y. Ouerdane, “X-ray irradiation effects on a multistep Ge-doped silica fiber produced using different drawing conditions,” J. Non-Cryst. Solids 357(8), 1966–1970 (2011).
[Crossref]

D. L. Griscom, “Trapped-electron centers in pure and doped glassy silica: A review and synthesis,” J. Non-Cryst. Solids 357(8), 1945–1962 (2011).
[Crossref]

A. Alessi, S. Girard, M. Cannas, S. Agnello, A. Boukenter, and Y. Ouerdane, “Evolution of Photo-induced defects in Ge-doped fiber/preform: influence of the drawing,” Opt. Express 19(12), 11680–11690 (2011).
[Crossref] [PubMed]

A. Alessi, S. Agnello, F. M. Gelardi, G. Messina, and M. Carpanese, “Influence of Ge doping level on the EPR signal of Ge(1), Ge(2) and E’Ge defects in Ge-doped silica,” J. Non-Cryst. Solids 357(8), 1900–1903 (2011).
[Crossref]

D. L. Griscom, “On the natures of radiation-induced point defects in GeO2-SiO2 glasses: reevaluation of a 26-year-old ESR and optical data set,” Opt. Mater. Express 1(3), 400–412 (2011).
[Crossref]

2010 (1)

D. Ceresoli, N. Marzari, M. G. Lopez, and T. Thonhauser, “Ab initio converse NMR approach for pseudopotentials”, Phys. Rev. B 81(18), 184424 (2010).
[Crossref]

2009 (3)

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
[Crossref] [PubMed]

L. Giacomazzi, P. Umari, and Alfredo Pasquarello, “Medium-range structure of vitreous SiO2 obtained through first-principles investigation of vibrational spectra,” Phys. Rev. B 79(6), 064202 (2009).
[Crossref]

A. Alessi, S. Agnello, S. Grandi, A. Parlato, and F. M. Gelardi, “Refractive index change dependence on Ge(1) defects in γ-irradiated Ge-doped silica,” Phys. Rev. B 80(1), 014103 (2009).
[Crossref]

2008 (2)

J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
[Crossref] [PubMed]

S. Agnello, A. Alessi, F.M. Gelardi, R. Boscaino, A. Parlato, S. Grandi, and A. Magistris, “Effect of oxygen deficiency on the radiation sensitivity of sol-gel Ge-doped amorphous SiO2,” Eur. Phys. J. B 61(1), 25–31 (2008).
[Crossref]

2007 (1)

M. F. Camellone, J. C. Reiner, U. Sennhauser, and L. Schlapbach, “Formation of electron traps in amorphous silica,” Phys. Rev. B 76(12), 125205 (2007).
[Crossref]

2006 (4)

L. Giacomazzi, P. Umari, and A. Pasquarello, “Vibrational spectra of vitreous germania from first-principles,” Phys. Rev. B 74(15), 155208 (2006).
[Crossref]

T. Uchino and T. Yoko, “Density functional theory of structural transformations of oxygen-deficient centers in amorphous silica during hole trapping: Structure and formation mechanism of the Eγ′ center,” Phys. Rev. B 74(12), 125203 (2006).
[Crossref]

G. Buscarino, S. Agnello, and F. M. Gelardi, “29Si Hyperfine Structure of the Eα′ Center in Amorphous Silicon Dioxide,” Phys. Rev. Lett. 97(13), 135502 (2006).
[Crossref] [PubMed]

R. F. Cuevas, E. H. Sekiya, A. Garcia-Quiroz, E. C. Da Silva, and C. K. Suzuki, “Effect of processing parameters on control of defect centers associated with second-order harmonic generation and photosensitivity in SiO2:GeO2 glass preforms,” Nucl. Instrum. Methods Phys. Res. B 247(2), 285–289 (2006).
[Crossref]

2005 (3)

N. Richard, L. Martin-Samos, G. Roma, Y. Limoge, and J. P. Crocombette, “First principle study of neutral and charged self-defects in amorphous SiO2,” J. Non-Cryst. Solids 351(21), 1825–1829 (2005).
[Crossref]

L. Martin-Samos, Y. Limoge, J.-P. Crocombette, G. Roma, N. Richard, E. Anglada, and E. Artacho, “Neutral self-defects in a silica model: A first-principles study,” Phys. Rev. B 71(1), 014116 (2005).
[Crossref]

L. Giacomazzi, P. Umari, and A. Pasquarello, “Medium-Range Structural Properties of Vitreous Germania Obtained through First-Principles Analysis of Vibrational Spectra,” Phys. Rev. Lett. 95(7), 075505 (2005).
[Crossref] [PubMed]

2004 (2)

S. Mukhopadhyay, P. V. Sushko, A. M. Stoneham, and A. L. Shluger, “Modeling of the structure and properties of oxygen vacancies in amorphous silica,” Phys. Rev. B 70(19), 195203 (2004).
[Crossref]

T. Tamura, G-H. Lu, M. Kohyama, and R. Yamammoto, “E′ center in Ge-doped SiO2 glass,” Phys. Rev. B 70(15), 153201 (2004).
[Crossref]

2003 (1)

A. Trukhin and B. Poumellec, “Photosensitivity of silica glass with germanium studied by photoinduced of thermally stimulated luminescence with vacuum ultraviolet radiation,” J. Non-Cryst. Solids 324(1), 21–28 (2003).
[Crossref]

2002 (2)

M. Yamaguchi, K. Saito, and A. J. Ikushima, “Formation and relaxation processes of photoinduced defects in a Ge-doped SiO2 glass,” Phys. Rev. B 66(13), 132106 (2002).
[Crossref]

C. J. Pickard and F. Mauri, “First-Principles Theory of the EPR g Tensor in Solids: Defects in Quartz,” Phys. Rev. Lett. 88(8), 086403 (2002).
[Crossref] [PubMed]

2001 (1)

T. Uchino, M. Takahashi, and T. Yoko, “Mechanism of electron trapping in Ge-doped SiO2 glass,” Appl. Phys. Lett. 79(3), 359–361 (2001).
[Crossref]

2000 (2)

T. Uchino, M. Takahashi, and T. Yoko, “Structure and Formation Mechanism of Ge E′ Center from Divalent Defects in Ge-doped SiO2 Glass,” Phys. Rev. Lett. 84(7), 1475–1478 (2000).
[Crossref] [PubMed]

G. Pacchioni and C. Mazzeo, “Paramagnetic centers in Ge-doped silica. A first-principles study,” Phys. Rev. B 62(9), 5452–5460 (2000).
[Crossref]

1999 (3)

M. Essid, J. Albert, J. L. Brebner, and K. Awazu, “Correlation between oxygen-deficient center concentration and KrF excimer laser induced defects in thermally annealed Ge-doped optical fiber preforms,” J. Non-Cryst. Solids 246(1), 39–45 (1999).
[Crossref]

N. Chiodini, F. Meinardi, F. Morazzoni, A. Paleari, and R. Scotti, “Optical transitions of paramagnetic Ge sites created by x-ray irradiation of oxygen-defect-free Ge-doped SiO2 by the sol-gel method,” Phys. Rev. B 60(4), 2429–2435 (1999).
[Crossref]

M. Fujimaki, T. Kasahara, S. Shimoto, N. Miyazaki, S. Tokuhiro, K. Soo Seol, and Y. Ohki, “Structural changes induced by KrF excimer laser photons in H2-loaded Ge-doped SiO2 glass,” Phys. Rev. B 60(7), 4682–4687 (1999).
[Crossref]

1998 (3)

M. Fujimaki, T. Watanabe, T. Katoh, T. Kasahara, N. Miyazaki, Y. Ohki, and H. Nishikawa, “Structures and generation mechanisms of paramagnetic centers and absorption bands responsible for Ge-doped SiO2 optical-fiber gratings,” Phys. Rev. B 57(7), 3920–3926 (1998).
[Crossref]

G. Pacchioni and R. Ferrario, “Optical transitions and EPR properties of two-coordinated Si, Ge, Sn and related H(I), H(II) and H(III) centers in pure and doped silica from ab initio calculations,” Phys. Rev. B 58(10), 6090–6096 (1998).
[Crossref]

D. L. Price, M. L. Saboungi, and A. C. Barnes, “Structure of Vitreous Germania,” Phys. Rev. Lett. 81(15), 3207–3210 (1998).
[Crossref]

1995 (1)

J. Nishii, K. Fukumi, H. Yamanaka, K. Kawamura, H. Hosono, and H. Kawazoe, “Photochemical reactions in GeO2-SiO2 glasses induced by ultraviolet irradiation: Comparison between Hg lamp and excimer laser,” Phys. Rev. B 52(3), 1661–1665 (1995).
[Crossref]

1993 (1)

M. Gallagher and U. Osterberg, “Spectroscopy of defects in germanium-doped silica glasses,” J. Appl. Phys. 74(4), 2771–2778 (1993).
[Crossref]

1992 (2)

L. Skuja, “Isoelectronic series of twofold coordinated Si, Ge, and Sn atoms in glassy SiO2: A luminescence study,” J. Non-Cryst. Solids,  149(1), 77–95 (1992).
[Crossref]

E.V. Anoikin, A.N. Guryanov, D.D. Gusovsky, E.M. Dianov, V.M. Mashinsky, S.I. Miroshnichenko, V.B. Neustruev, V.A. Tikhomirov, and Yu.B. Zverev, “UV and gamma radiation damage in silica glass and fibres doped with germanium and cerium,” Nucl. Instrum. Methods Phys. Res. B 65(1), 392–396 (1992).
[Crossref]

1988 (3)

A. D. Becke, “Density-functional exchange-energy approximation with correct asymptotic behavior,” Phys. Rev. A 38(6), 3098–3100 (1988).
[Crossref] [PubMed]

C. Lee, W. Yang, and R. G. Parr, “Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density,” Phys. Rev. B 37(2), 785–789 (1988).
[Crossref]

K. Nagasawa, T. Fujii, Y. Ohki, and Y. Hama, “Relation between Ge(2) Center and 11.9 mT Hyperfine Structure of ESR Spectra in Ge-doped Silica Fibers,” Japan. J. Appl. Phys. 27(2A), L240–L243 (1988).
[Crossref]

1987 (1)

T. E. Tsai, D. L. Griscom, E. J. Friebele, and J. W. Fleming ,“Radiation induced defect centers in high purity GeO2 glass,” J. Appl. Phys. 62(6), 2264–2268 (1987).
[Crossref]

1982 (1)

A. C. Wright, G. Etherington, J. A. E. Desa, R. N. Sinclair, G. A. N. Connell, and J. C. Mikkelsen, “Neutron amorphography,”, J. Non-Cryst. Solids 49(1), 63–102 (1982).
[Crossref]

1978 (1)

J. Isoya, J. A. Weil, and R. F. C. Claridge, “The dynamic interchange and relationship between germanium centers in quartz,” J. Chem. Phys. 69(11), 4876–4884 (1978).
[Crossref]

1974 (1)

E. J. Friebele, D. L. Griscom, and G. H. Sigel, “Defect centers in a germanium-doped silica-core optical fiber,” J. Appl. Phys. 45(8), 3424–3428 (1974).
[Crossref]

1971 (1)

G. F. J. Garlick, J. E. Nicholls, and A. M. Özer, “Electron spin resonance of electron irradiated germanium dioxide,” J. Phys. C: Solid St. Phys. 4(14), 2230–2239 (1971).
[Crossref]

1965 (1)

R. A. Weeks and T. Purcell, “Electron Spin Resonance and Optical Absorption in GeO2,” J. Chem. Phys. 43(2), 483–491 (1965).
[Crossref]

Afanas’ev, V. V.

A. M. El-Sayed, M. B. Watkins, V. V. Afanas’ev, and A. L. Shluger, “Nature of intrinsic and extrinsic electron trapping in SiO2,” Phys. Rev. B 89(12), 125201 (2014).
[Crossref]

M. Houssa, G. Pourtois, V. V. Afanas’ev, and A. Stesmans, “First-principles study of Ge dangling bonds in GeO2 and correlation with electron spin resonance at Ge/GeO2 interfaces,” Appl. Phys. Lett. 99(21), 212103 (2011).
[Crossref]

Agnello, S.

A. Alessi, S. Girard, C. Marcandella, S. Agnello, M. Cannas, A. Boukenter, and Y. Ouerdane, “X-ray irradiation effects on a multistep Ge-doped silica fiber produced using different drawing conditions,” J. Non-Cryst. Solids 357(8), 1966–1970 (2011).
[Crossref]

A. Alessi, S. Agnello, F. M. Gelardi, G. Messina, and M. Carpanese, “Influence of Ge doping level on the EPR signal of Ge(1), Ge(2) and E’Ge defects in Ge-doped silica,” J. Non-Cryst. Solids 357(8), 1900–1903 (2011).
[Crossref]

A. Alessi, S. Girard, M. Cannas, S. Agnello, A. Boukenter, and Y. Ouerdane, “Evolution of Photo-induced defects in Ge-doped fiber/preform: influence of the drawing,” Opt. Express 19(12), 11680–11690 (2011).
[Crossref] [PubMed]

A. Alessi, S. Agnello, S. Grandi, A. Parlato, and F. M. Gelardi, “Refractive index change dependence on Ge(1) defects in γ-irradiated Ge-doped silica,” Phys. Rev. B 80(1), 014103 (2009).
[Crossref]

S. Agnello, A. Alessi, F.M. Gelardi, R. Boscaino, A. Parlato, S. Grandi, and A. Magistris, “Effect of oxygen deficiency on the radiation sensitivity of sol-gel Ge-doped amorphous SiO2,” Eur. Phys. J. B 61(1), 25–31 (2008).
[Crossref]

G. Buscarino, S. Agnello, and F. M. Gelardi, “29Si Hyperfine Structure of the Eα′ Center in Amorphous Silicon Dioxide,” Phys. Rev. Lett. 97(13), 135502 (2006).
[Crossref] [PubMed]

Albert, J.

M. Essid, J. Albert, J. L. Brebner, and K. Awazu, “Correlation between oxygen-deficient center concentration and KrF excimer laser induced defects in thermally annealed Ge-doped optical fiber preforms,” J. Non-Cryst. Solids 246(1), 39–45 (1999).
[Crossref]

Alessi, A.

A. Alessi, S. Agnello, F. M. Gelardi, G. Messina, and M. Carpanese, “Influence of Ge doping level on the EPR signal of Ge(1), Ge(2) and E’Ge defects in Ge-doped silica,” J. Non-Cryst. Solids 357(8), 1900–1903 (2011).
[Crossref]

A. Alessi, S. Girard, C. Marcandella, S. Agnello, M. Cannas, A. Boukenter, and Y. Ouerdane, “X-ray irradiation effects on a multistep Ge-doped silica fiber produced using different drawing conditions,” J. Non-Cryst. Solids 357(8), 1966–1970 (2011).
[Crossref]

A. Alessi, S. Girard, M. Cannas, S. Agnello, A. Boukenter, and Y. Ouerdane, “Evolution of Photo-induced defects in Ge-doped fiber/preform: influence of the drawing,” Opt. Express 19(12), 11680–11690 (2011).
[Crossref] [PubMed]

A. Alessi, S. Agnello, S. Grandi, A. Parlato, and F. M. Gelardi, “Refractive index change dependence on Ge(1) defects in γ-irradiated Ge-doped silica,” Phys. Rev. B 80(1), 014103 (2009).
[Crossref]

S. Agnello, A. Alessi, F.M. Gelardi, R. Boscaino, A. Parlato, S. Grandi, and A. Magistris, “Effect of oxygen deficiency on the radiation sensitivity of sol-gel Ge-doped amorphous SiO2,” Eur. Phys. J. B 61(1), 25–31 (2008).
[Crossref]

Anglada, E.

L. Martin-Samos, Y. Limoge, J.-P. Crocombette, G. Roma, N. Richard, E. Anglada, and E. Artacho, “Neutral self-defects in a silica model: A first-principles study,” Phys. Rev. B 71(1), 014116 (2005).
[Crossref]

Anoikin, E.V.

E.V. Anoikin, A.N. Guryanov, D.D. Gusovsky, E.M. Dianov, V.M. Mashinsky, S.I. Miroshnichenko, V.B. Neustruev, V.A. Tikhomirov, and Yu.B. Zverev, “UV and gamma radiation damage in silica glass and fibres doped with germanium and cerium,” Nucl. Instrum. Methods Phys. Res. B 65(1), 392–396 (1992).
[Crossref]

Artacho, E.

L. Martin-Samos, Y. Limoge, J.-P. Crocombette, G. Roma, N. Richard, E. Anglada, and E. Artacho, “Neutral self-defects in a silica model: A first-principles study,” Phys. Rev. B 71(1), 014116 (2005).
[Crossref]

Astakhov, O.

M. Fehr, A. Schnegg, B. Rech, K. Lips, O. Astakhov, F. Finger, G. Pfanner, C. Freysoldt, J. Neugebauer, R. Bittl, and C. Teutloff, “Combined multifrequency EPR and DFT study of dangling bonds in a-Si:H,” Phys. Rev. B 84(24), 245203 (2011).
[Crossref]

Awazu, K.

M. Essid, J. Albert, J. L. Brebner, and K. Awazu, “Correlation between oxygen-deficient center concentration and KrF excimer laser induced defects in thermally annealed Ge-doped optical fiber preforms,” J. Non-Cryst. Solids 246(1), 39–45 (1999).
[Crossref]

Baggio, J.

J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
[Crossref] [PubMed]

Barnes, A. C.

D. L. Price, M. L. Saboungi, and A. C. Barnes, “Structure of Vitreous Germania,” Phys. Rev. Lett. 81(15), 3207–3210 (1998).
[Crossref]

Baroni, S.

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
[Crossref] [PubMed]

Becke, A. D.

A. D. Becke, “Density-functional exchange-energy approximation with correct asymptotic behavior,” Phys. Rev. A 38(6), 3098–3100 (1988).
[Crossref] [PubMed]

Bertalot, L.

J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
[Crossref] [PubMed]

Bittl, R.

M. Fehr, A. Schnegg, B. Rech, K. Lips, O. Astakhov, F. Finger, G. Pfanner, C. Freysoldt, J. Neugebauer, R. Bittl, and C. Teutloff, “Combined multifrequency EPR and DFT study of dangling bonds in a-Si:H,” Phys. Rev. B 84(24), 245203 (2011).
[Crossref]

Bonini, N.

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
[Crossref] [PubMed]

Boscaino, R.

S. Agnello, A. Alessi, F.M. Gelardi, R. Boscaino, A. Parlato, S. Grandi, and A. Magistris, “Effect of oxygen deficiency on the radiation sensitivity of sol-gel Ge-doped amorphous SiO2,” Eur. Phys. J. B 61(1), 25–31 (2008).
[Crossref]

Boukenter, A.

L. Giacomazzi, L. Martin-Samos, A. Boukenter, Y. Ouerdane, S. Girard, and N. Richard, “EPR parameters of E′ centers in v-SiO2 from first-principles calculations,” Phys. Rev. B 90(1), 014108 (2014).
[Crossref]

N. Richard, L. Martin-Samos, S. Girard, A. Ruini, A. Boukenter, Y. Ouerdane, and J-P Meunier, “Oxygen deficient centers in silica: optical properties within many-body perturbation theory,” J. Phys. Condens. Matter 25(33), 335502 (2013).
[Crossref] [PubMed]

S. Girard, J. Kuhnhenn, A. Gusarov, B. Brichard, M. Van Uffelen, Y. Ouerdane, A. Boukenter, and C. Marcandella, “Radiation Effects on Silica-Based Optical Fibers: Recent Advances and Future Challenges,” IEEE Trans. Nucl. Sci. 60(3), 2015–2036 (2013).
[Crossref]

A. Alessi, S. Girard, C. Marcandella, S. Agnello, M. Cannas, A. Boukenter, and Y. Ouerdane, “X-ray irradiation effects on a multistep Ge-doped silica fiber produced using different drawing conditions,” J. Non-Cryst. Solids 357(8), 1966–1970 (2011).
[Crossref]

A. Alessi, S. Girard, M. Cannas, S. Agnello, A. Boukenter, and Y. Ouerdane, “Evolution of Photo-induced defects in Ge-doped fiber/preform: influence of the drawing,” Opt. Express 19(12), 11680–11690 (2011).
[Crossref] [PubMed]

Bourgade, J. L.

J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
[Crossref] [PubMed]

Brebner, J. L.

M. Essid, J. Albert, J. L. Brebner, and K. Awazu, “Correlation between oxygen-deficient center concentration and KrF excimer laser induced defects in thermally annealed Ge-doped optical fiber preforms,” J. Non-Cryst. Solids 246(1), 39–45 (1999).
[Crossref]

Brichard, B.

S. Girard, J. Kuhnhenn, A. Gusarov, B. Brichard, M. Van Uffelen, Y. Ouerdane, A. Boukenter, and C. Marcandella, “Radiation Effects on Silica-Based Optical Fibers: Recent Advances and Future Challenges,” IEEE Trans. Nucl. Sci. 60(3), 2015–2036 (2013).
[Crossref]

J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
[Crossref] [PubMed]

Buscarino, G.

G. Buscarino, S. Agnello, and F. M. Gelardi, “29Si Hyperfine Structure of the Eα′ Center in Amorphous Silicon Dioxide,” Phys. Rev. Lett. 97(13), 135502 (2006).
[Crossref] [PubMed]

Calandra, M.

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
[Crossref] [PubMed]

Camellone, M. F.

M. F. Camellone, J. C. Reiner, U. Sennhauser, and L. Schlapbach, “Formation of electron traps in amorphous silica,” Phys. Rev. B 76(12), 125205 (2007).
[Crossref]

Cannas, M.

A. Alessi, S. Girard, M. Cannas, S. Agnello, A. Boukenter, and Y. Ouerdane, “Evolution of Photo-induced defects in Ge-doped fiber/preform: influence of the drawing,” Opt. Express 19(12), 11680–11690 (2011).
[Crossref] [PubMed]

A. Alessi, S. Girard, C. Marcandella, S. Agnello, M. Cannas, A. Boukenter, and Y. Ouerdane, “X-ray irradiation effects on a multistep Ge-doped silica fiber produced using different drawing conditions,” J. Non-Cryst. Solids 357(8), 1966–1970 (2011).
[Crossref]

Car, R

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
[Crossref] [PubMed]

Carpanese, M.

A. Alessi, S. Agnello, F. M. Gelardi, G. Messina, and M. Carpanese, “Influence of Ge doping level on the EPR signal of Ge(1), Ge(2) and E’Ge defects in Ge-doped silica,” J. Non-Cryst. Solids 357(8), 1900–1903 (2011).
[Crossref]

Cavazzoni, C.

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
[Crossref] [PubMed]

Ceresoli, D.

D. Ceresoli, N. Marzari, M. G. Lopez, and T. Thonhauser, “Ab initio converse NMR approach for pseudopotentials”, Phys. Rev. B 81(18), 184424 (2010).
[Crossref]

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
[Crossref] [PubMed]

Chiarotti, G. L.

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
[Crossref] [PubMed]

Chiodini, N.

N. Chiodini, F. Meinardi, F. Morazzoni, A. Paleari, and R. Scotti, “Optical transitions of paramagnetic Ge sites created by x-ray irradiation of oxygen-defect-free Ge-doped SiO2 by the sol-gel method,” Phys. Rev. B 60(4), 2429–2435 (1999).
[Crossref]

Claridge, R. F. C.

J. Isoya, J. A. Weil, and R. F. C. Claridge, “The dynamic interchange and relationship between germanium centers in quartz,” J. Chem. Phys. 69(11), 4876–4884 (1978).
[Crossref]

Cococcioni, M.

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
[Crossref] [PubMed]

Connell, G. A. N.

A. C. Wright, G. Etherington, J. A. E. Desa, R. N. Sinclair, G. A. N. Connell, and J. C. Mikkelsen, “Neutron amorphography,”, J. Non-Cryst. Solids 49(1), 63–102 (1982).
[Crossref]

Costley, A. E.

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J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
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Gelardi, F.M.

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P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
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Giannozzi, P.

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
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Girard, S.

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A. Alessi, S. Girard, C. Marcandella, S. Agnello, M. Cannas, A. Boukenter, and Y. Ouerdane, “X-ray irradiation effects on a multistep Ge-doped silica fiber produced using different drawing conditions,” J. Non-Cryst. Solids 357(8), 1966–1970 (2011).
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Glebov, V.

J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
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Gougoussis, C.

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
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Grandi, S.

A. Alessi, S. Agnello, S. Grandi, A. Parlato, and F. M. Gelardi, “Refractive index change dependence on Ge(1) defects in γ-irradiated Ge-doped silica,” Phys. Rev. B 80(1), 014103 (2009).
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S. Agnello, A. Alessi, F.M. Gelardi, R. Boscaino, A. Parlato, S. Grandi, and A. Magistris, “Effect of oxygen deficiency on the radiation sensitivity of sol-gel Ge-doped amorphous SiO2,” Eur. Phys. J. B 61(1), 25–31 (2008).
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Griscom, D. L.

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D. L. Griscom, “On the natures of radiation-induced point defects in GeO2-SiO2 glasses: reevaluation of a 26-year-old ESR and optical data set,” Opt. Mater. Express 1(3), 400–412 (2011).
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Guryanov, A.N.

E.V. Anoikin, A.N. Guryanov, D.D. Gusovsky, E.M. Dianov, V.M. Mashinsky, S.I. Miroshnichenko, V.B. Neustruev, V.A. Tikhomirov, and Yu.B. Zverev, “UV and gamma radiation damage in silica glass and fibres doped with germanium and cerium,” Nucl. Instrum. Methods Phys. Res. B 65(1), 392–396 (1992).
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Gusarov, A.

S. Girard, J. Kuhnhenn, A. Gusarov, B. Brichard, M. Van Uffelen, Y. Ouerdane, A. Boukenter, and C. Marcandella, “Radiation Effects on Silica-Based Optical Fibers: Recent Advances and Future Challenges,” IEEE Trans. Nucl. Sci. 60(3), 2015–2036 (2013).
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Gusovsky, D.D.

E.V. Anoikin, A.N. Guryanov, D.D. Gusovsky, E.M. Dianov, V.M. Mashinsky, S.I. Miroshnichenko, V.B. Neustruev, V.A. Tikhomirov, and Yu.B. Zverev, “UV and gamma radiation damage in silica glass and fibres doped with germanium and cerium,” Nucl. Instrum. Methods Phys. Res. B 65(1), 392–396 (1992).
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Hama, Y.

K. Nagasawa, T. Fujii, Y. Ohki, and Y. Hama, “Relation between Ge(2) Center and 11.9 mT Hyperfine Structure of ESR Spectra in Ge-doped Silica Fibers,” Japan. J. Appl. Phys. 27(2A), L240–L243 (1988).
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J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
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J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
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M. Fujimaki, T. Kasahara, S. Shimoto, N. Miyazaki, S. Tokuhiro, K. Soo Seol, and Y. Ohki, “Structural changes induced by KrF excimer laser photons in H2-loaded Ge-doped SiO2 glass,” Phys. Rev. B 60(7), 4682–4687 (1999).
[Crossref]

M. Fujimaki, T. Watanabe, T. Katoh, T. Kasahara, N. Miyazaki, Y. Ohki, and H. Nishikawa, “Structures and generation mechanisms of paramagnetic centers and absorption bands responsible for Ge-doped SiO2 optical-fiber gratings,” Phys. Rev. B 57(7), 3920–3926 (1998).
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M. Fujimaki, T. Watanabe, T. Katoh, T. Kasahara, N. Miyazaki, Y. Ohki, and H. Nishikawa, “Structures and generation mechanisms of paramagnetic centers and absorption bands responsible for Ge-doped SiO2 optical-fiber gratings,” Phys. Rev. B 57(7), 3920–3926 (1998).
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J. Nishii, K. Fukumi, H. Yamanaka, K. Kawamura, H. Hosono, and H. Kawazoe, “Photochemical reactions in GeO2-SiO2 glasses induced by ultraviolet irradiation: Comparison between Hg lamp and excimer laser,” Phys. Rev. B 52(3), 1661–1665 (1995).
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J. Nishii, K. Fukumi, H. Yamanaka, K. Kawamura, H. Hosono, and H. Kawazoe, “Photochemical reactions in GeO2-SiO2 glasses induced by ultraviolet irradiation: Comparison between Hg lamp and excimer laser,” Phys. Rev. B 52(3), 1661–1665 (1995).
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T. Tamura, G-H. Lu, M. Kohyama, and R. Yamammoto, “E′ center in Ge-doped SiO2 glass,” Phys. Rev. B 70(15), 153201 (2004).
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P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
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S. Girard, J. Kuhnhenn, A. Gusarov, B. Brichard, M. Van Uffelen, Y. Ouerdane, A. Boukenter, and C. Marcandella, “Radiation Effects on Silica-Based Optical Fibers: Recent Advances and Future Challenges,” IEEE Trans. Nucl. Sci. 60(3), 2015–2036 (2013).
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P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
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J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
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J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
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R. I. Mashkovtsev, Z. Li, M. Mao, and Y. Pan, “73Ge, 17O and 29Si hyperfine interactions of the Ge E1′ center in crystalline SiO2,” J. Magn. Resonance 233, 7–16 (2013).
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T. Tamura, G-H. Lu, M. Kohyama, and R. Yamammoto, “E′ center in Ge-doped SiO2 glass,” Phys. Rev. B 70(15), 153201 (2004).
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S. Agnello, A. Alessi, F.M. Gelardi, R. Boscaino, A. Parlato, S. Grandi, and A. Magistris, “Effect of oxygen deficiency on the radiation sensitivity of sol-gel Ge-doped amorphous SiO2,” Eur. Phys. J. B 61(1), 25–31 (2008).
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R. I. Mashkovtsev, Z. Li, M. Mao, and Y. Pan, “73Ge, 17O and 29Si hyperfine interactions of the Ge E1′ center in crystalline SiO2,” J. Magn. Resonance 233, 7–16 (2013).
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Marcandella, C.

S. Girard, J. Kuhnhenn, A. Gusarov, B. Brichard, M. Van Uffelen, Y. Ouerdane, A. Boukenter, and C. Marcandella, “Radiation Effects on Silica-Based Optical Fibers: Recent Advances and Future Challenges,” IEEE Trans. Nucl. Sci. 60(3), 2015–2036 (2013).
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A. Alessi, S. Girard, C. Marcandella, S. Agnello, M. Cannas, A. Boukenter, and Y. Ouerdane, “X-ray irradiation effects on a multistep Ge-doped silica fiber produced using different drawing conditions,” J. Non-Cryst. Solids 357(8), 1966–1970 (2011).
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L. Giacomazzi, L. Martin-Samos, A. Boukenter, Y. Ouerdane, S. Girard, and N. Richard, “EPR parameters of E′ centers in v-SiO2 from first-principles calculations,” Phys. Rev. B 90(1), 014108 (2014).
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N. Richard, L. Martin-Samos, S. Girard, A. Ruini, A. Boukenter, Y. Ouerdane, and J-P Meunier, “Oxygen deficient centers in silica: optical properties within many-body perturbation theory,” J. Phys. Condens. Matter 25(33), 335502 (2013).
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P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
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N. Richard, L. Martin-Samos, G. Roma, Y. Limoge, and J. P. Crocombette, “First principle study of neutral and charged self-defects in amorphous SiO2,” J. Non-Cryst. Solids 351(21), 1825–1829 (2005).
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L. Martin-Samos, Y. Limoge, J.-P. Crocombette, G. Roma, N. Richard, E. Anglada, and E. Artacho, “Neutral self-defects in a silica model: A first-principles study,” Phys. Rev. B 71(1), 014116 (2005).
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L. Giacomazzi, L. Martin-Samos, and N. Richard, “Paramagnetic centers in a-GeO2” submitted (2015).

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D. Ceresoli, N. Marzari, M. G. Lopez, and T. Thonhauser, “Ab initio converse NMR approach for pseudopotentials”, Phys. Rev. B 81(18), 184424 (2010).
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P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
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R. I. Mashkovtsev, Z. Li, M. Mao, and Y. Pan, “73Ge, 17O and 29Si hyperfine interactions of the Ge E1′ center in crystalline SiO2,” J. Magn. Resonance 233, 7–16 (2013).
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P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, Ismaila Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, and R. M. Wentzcovitch, “QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials,” J. Phys. Condens. Matter 21(39), 395502 (2009).
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N. Chiodini, F. Meinardi, F. Morazzoni, A. Paleari, and R. Scotti, “Optical transitions of paramagnetic Ge sites created by x-ray irradiation of oxygen-defect-free Ge-doped SiO2 by the sol-gel method,” Phys. Rev. B 60(4), 2429–2435 (1999).
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N. Richard, L. Martin-Samos, S. Girard, A. Ruini, A. Boukenter, Y. Ouerdane, and J-P Meunier, “Oxygen deficient centers in silica: optical properties within many-body perturbation theory,” J. Phys. Condens. Matter 25(33), 335502 (2013).
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Miyazaki, N.

M. Fujimaki, T. Kasahara, S. Shimoto, N. Miyazaki, S. Tokuhiro, K. Soo Seol, and Y. Ohki, “Structural changes induced by KrF excimer laser photons in H2-loaded Ge-doped SiO2 glass,” Phys. Rev. B 60(7), 4682–4687 (1999).
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M. Fujimaki, T. Watanabe, T. Katoh, T. Kasahara, N. Miyazaki, Y. Ohki, and H. Nishikawa, “Structures and generation mechanisms of paramagnetic centers and absorption bands responsible for Ge-doped SiO2 optical-fiber gratings,” Phys. Rev. B 57(7), 3920–3926 (1998).
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J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
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N. Chiodini, F. Meinardi, F. Morazzoni, A. Paleari, and R. Scotti, “Optical transitions of paramagnetic Ge sites created by x-ray irradiation of oxygen-defect-free Ge-doped SiO2 by the sol-gel method,” Phys. Rev. B 60(4), 2429–2435 (1999).
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J. L. Bourgade, A. E. Costley, R. Reichle, E. R. Hodgson, W. Hsing, V. Glebov, M. Decreton, R. Leeper, J. L. Leray, M. Dentan, T. Hutter, A. Moroño, D. Eder, W. Shmayda, B. Brichard, J. Baggio, L. Bertalot, G. Vayakis, M. Moran, T. C. Sangster, L. Vermeeren, C. Stoeckl, S. Girard, and G. Pien, “Diagnostic components in harsh radiation environments: possible overlap in R&D requirements of inertial confinement and magnetic fusion systems,” Rev. Sci. Instrum. 79(10), 10F304 (2008).
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K. Nagasawa, T. Fujii, Y. Ohki, and Y. Hama, “Relation between Ge(2) Center and 11.9 mT Hyperfine Structure of ESR Spectra in Ge-doped Silica Fibers,” Japan. J. Appl. Phys. 27(2A), L240–L243 (1988).
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M. Fehr, A. Schnegg, B. Rech, K. Lips, O. Astakhov, F. Finger, G. Pfanner, C. Freysoldt, J. Neugebauer, R. Bittl, and C. Teutloff, “Combined multifrequency EPR and DFT study of dangling bonds in a-Si:H,” Phys. Rev. B 84(24), 245203 (2011).
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Neustruev, V.B.

E.V. Anoikin, A.N. Guryanov, D.D. Gusovsky, E.M. Dianov, V.M. Mashinsky, S.I. Miroshnichenko, V.B. Neustruev, V.A. Tikhomirov, and Yu.B. Zverev, “UV and gamma radiation damage in silica glass and fibres doped with germanium and cerium,” Nucl. Instrum. Methods Phys. Res. B 65(1), 392–396 (1992).
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Nishii, J.

J. Nishii, K. Fukumi, H. Yamanaka, K. Kawamura, H. Hosono, and H. Kawazoe, “Photochemical reactions in GeO2-SiO2 glasses induced by ultraviolet irradiation: Comparison between Hg lamp and excimer laser,” Phys. Rev. B 52(3), 1661–1665 (1995).
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Nishikawa, H.

M. Fujimaki, T. Watanabe, T. Katoh, T. Kasahara, N. Miyazaki, Y. Ohki, and H. Nishikawa, “Structures and generation mechanisms of paramagnetic centers and absorption bands responsible for Ge-doped SiO2 optical-fiber gratings,” Phys. Rev. B 57(7), 3920–3926 (1998).
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Ohki, Y.

M. Fujimaki, T. Kasahara, S. Shimoto, N. Miyazaki, S. Tokuhiro, K. Soo Seol, and Y. Ohki, “Structural changes induced by KrF excimer laser photons in H2-loaded Ge-doped SiO2 glass,” Phys. Rev. B 60(7), 4682–4687 (1999).
[Crossref]

M. Fujimaki, T. Watanabe, T. Katoh, T. Kasahara, N. Miyazaki, Y. Ohki, and H. Nishikawa, “Structures and generation mechanisms of paramagnetic centers and absorption bands responsible for Ge-doped SiO2 optical-fiber gratings,” Phys. Rev. B 57(7), 3920–3926 (1998).
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K. Nagasawa, T. Fujii, Y. Ohki, and Y. Hama, “Relation between Ge(2) Center and 11.9 mT Hyperfine Structure of ESR Spectra in Ge-doped Silica Fibers,” Japan. J. Appl. Phys. 27(2A), L240–L243 (1988).
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L. Giacomazzi, L. Martin-Samos, A. Boukenter, Y. Ouerdane, S. Girard, and N. Richard, “EPR parameters of E′ centers in v-SiO2 from first-principles calculations,” Phys. Rev. B 90(1), 014108 (2014).
[Crossref]

S. Girard, J. Kuhnhenn, A. Gusarov, B. Brichard, M. Van Uffelen, Y. Ouerdane, A. Boukenter, and C. Marcandella, “Radiation Effects on Silica-Based Optical Fibers: Recent Advances and Future Challenges,” IEEE Trans. Nucl. Sci. 60(3), 2015–2036 (2013).
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N. Richard, L. Martin-Samos, S. Girard, A. Ruini, A. Boukenter, Y. Ouerdane, and J-P Meunier, “Oxygen deficient centers in silica: optical properties within many-body perturbation theory,” J. Phys. Condens. Matter 25(33), 335502 (2013).
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A. Alessi, S. Girard, C. Marcandella, S. Agnello, M. Cannas, A. Boukenter, and Y. Ouerdane, “X-ray irradiation effects on a multistep Ge-doped silica fiber produced using different drawing conditions,” J. Non-Cryst. Solids 357(8), 1966–1970 (2011).
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A. Alessi, S. Girard, M. Cannas, S. Agnello, A. Boukenter, and Y. Ouerdane, “Evolution of Photo-induced defects in Ge-doped fiber/preform: influence of the drawing,” Opt. Express 19(12), 11680–11690 (2011).
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G. F. J. Garlick, J. E. Nicholls, and A. M. Özer, “Electron spin resonance of electron irradiated germanium dioxide,” J. Phys. C: Solid St. Phys. 4(14), 2230–2239 (1971).
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Rev. Sci. Instrum. (1)

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Other (7)

D. L. Griscom, “A Minireview of the Natures of Radiation-Induced Point Defects in Pure and Doped Silica Glasses and Their Visible/Near-IR Absorption Bands, with Emphasis on Self-Trapped Holes and How They Can Be Controlled,” Phys. Res. Intern.2013(379041), http://dx.doi.org/10.1155/2013/379041

Specialty Optical Fibers HandbookA. Mendez and T. F. Morse eds., (Academic Press, 2007).

Calculations of the Aiso(73Ge) Fermi contact quite often show differences of a few mT with respect to experimental values [6, 20, 52, 59]

D. L. Griscom, “Electron Spin Resonance,” in Glass science and technology: Advances In Structural Analysis Vol. 4B, D.R. Uhlmann and N.J. Kreidl, eds. (Academic Press, 1990).
[Crossref]

The calculated Aiso(73Ge) of Ge-E′ -like and Ge-FO configurations underestimate by 8% and 13% the experimental data given in Table 1 for Ge-E′ and Ge(2). The discrepancy (5%) might be explained by the fact that the experimental Ge(2) values were obtained under the single-trapped electron at a four-fold Ge atom hypothesis [i.e. similar Fermi contact as Ge(1)] and might be reconsidered at the light of the present work.

L. Giacomazzi, L. Martin-Samos, and N. Richard, “Paramagnetic centers in a-GeO2” submitted (2015).

The increase of the g3 value in v-GeO2 with respect to Ge-doped silica should be related to the shortening of the longest Ge-O bond in Ge-FO configurations [45].

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Figures (4)

Fig. 1
Fig. 1 Schemes of the average atomic structure of (a) the Ge-FO configuration, (b) the ionized (non-relaxed) two-fold Ge configuration and (c) the single-trapped electron (STE) configuration at a fourfold Ge atom. O (black discs), Si (circles) and Ge (gray disc) atoms and the unpaired electron (dot) are shown together with Ge-O bond lengths. Ball and stick models and spin densities (shadowed) of a (d) Ge forward-oriented (FO) configuration, (e) a two-fold Ge configuration, and (f) a STE configuration. O atoms (red), Si atoms (light brown) and Ge atom (violet) are shown.
Fig. 2
Fig. 2 Aiso(73Ge) Fermi contacts of Ge-E′ -like (squares) and FO (circles) configurations plotted vs (a) g2 and (b) g3 principal values. Experimental data (discs) for Ge-E′ and Ge(2) centers are taken from [54,55]. (c) Experimental relative difference between (Δgi) g-values of Ge(2) and Ge-E′ centers plotted versus calculated average Δgi differences between Ge-FO and Ge-E′-like configurations. The size of the symbols represents the experimental error as in [28], while horizontal error bars shows the theoretical spread of the distributions of g2 and g3 values. The dotted line indicates identity between theory and experiments.
Fig. 3
Fig. 3 Calculated (a) g2 and (b) g3 principal values obtained [45] for SiODC configurations [E′ -like (squares) and FO (circles)] plotted vs g2 and g3 values obtained for the corresponding GeODC configuration. Experimental data (discs) for Si-E′, Ge-E′, E α and Ge(2) centers are taken from [10, 36, 54].
Fig. 4
Fig. 4 Calculated (a) g13 value vs distorption parameter δV of the Ge tetrahedron [57] and (b) O-Ge-O angle vs δV in our STE configurations. (c) Comparison of the g-values of the STE (filled squares) and Ge-FO (discs) configurations with respectively the g-values of the Ge(II) and Ge(I) centers detected in irradiated Ge-doped quartz [32]. Superimposed (empty symbols) comparison of the g-values of the Ge(1) and Ge(2) centers with respectively the g-values of the Ge(II) and Ge(I) [10,55]. The dotted line represents 100% agreement. A rigid shift of −900 ppm has been applied to calculated g-values of STE and GeFO configurations.

Tables (1)

Tables Icon

Table 1 Configuration type, calculated average g-values and Fermi contacts [Aiso(73Ge)] of Ge-FO and Ge-E′ -like and STE configurations in Ge-doped v-SiO2 compared to available experimental data for the Ge(2), Ge-E′ and Ge(1) centers. Theoretical results are also given for the non-relaxed GLPC+ configuration [Fig. 1(b)] and Ge-FO configurations in pure v-GeO2. Standard deviations and experimental errors (when available) are given in parenthesis. (g12 = g1 − g2 and g13 = g1 − g3).

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