Hydrogen-Related Paramagnetic Centers in Ge-Doped Sol-Gel Silica Induced by γ-Ray Irradiation

Simonpietro Agnello, Roberto Boscaino, Magistris, Stefania Grandi

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3 Citazioni (Scopus)

Abstract

We have studied the generation mechanisms of H(II) paramagnetic centers in Ge-doped silica by investigating up to 104 mol ppm sol-gel Ge-doped silica materials. We have considered materials with the same concentrations of Ge but that are produced by two different densification routes that give rise to different concentrations of Ge-related oxygen deficient centers (GeODC(II)). These centers are characterized by an optical absorption band at ∼ 5.2 eV (B2 β band) and two related emissions at ∼ 3.2 eV and ∼ 4.3 eV. The GeODC(II) content was estimated by absorption and emission measurements. The H(II) centers were induced by room temperature γ-ray irradiation and their concentration was determined by electron paramagnetic resonance measurements. The comparison between the two kinds of materials, obtained by different preparations, shows that the GeODC(II) concentration increases with the Ge content and is enhanced by vacuum densification. The comparison of irradiated samples shows that beyond the already known process of conversion of preexisting GeODC(II) into H(II) centers, another generation process of H(II) centers is effective that involves irradiation induced GeODC(II)
Lingua originaleEnglish
pagine (da-a)63-68
Numero di pagine6
RivistaJournal of Sol-Gel Science and Technology
Volume37
Stato di pubblicazionePublished - 2006

Fingerprint

Silica Gel
silica gel
Sol-gels
Hydrogen
rays
Silica
Irradiation
irradiation
hydrogen
densification
Densification
Silicon Dioxide
silicon dioxide
Light absorption
Paramagnetic resonance
Absorption spectra
electron paramagnetic resonance
optical absorption
routes
gels

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Chemistry(all)
  • Biomaterials
  • Condensed Matter Physics
  • Materials Chemistry

Cita questo

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title = "Hydrogen-Related Paramagnetic Centers in Ge-Doped Sol-Gel Silica Induced by γ-Ray Irradiation",
abstract = "We have studied the generation mechanisms of H(II) paramagnetic centers in Ge-doped silica by investigating up to 104 mol ppm sol-gel Ge-doped silica materials. We have considered materials with the same concentrations of Ge but that are produced by two different densification routes that give rise to different concentrations of Ge-related oxygen deficient centers (GeODC(II)). These centers are characterized by an optical absorption band at ∼ 5.2 eV (B2 β band) and two related emissions at ∼ 3.2 eV and ∼ 4.3 eV. The GeODC(II) content was estimated by absorption and emission measurements. The H(II) centers were induced by room temperature γ-ray irradiation and their concentration was determined by electron paramagnetic resonance measurements. The comparison between the two kinds of materials, obtained by different preparations, shows that the GeODC(II) concentration increases with the Ge content and is enhanced by vacuum densification. The comparison of irradiated samples shows that beyond the already known process of conversion of preexisting GeODC(II) into H(II) centers, another generation process of H(II) centers is effective that involves irradiation induced GeODC(II)",
author = "Simonpietro Agnello and Roberto Boscaino and Magistris and Stefania Grandi",
year = "2006",
language = "English",
volume = "37",
pages = "63--68",
journal = "Journal of Sol-Gel Science and Technology",
issn = "0928-0707",
publisher = "Springer Netherlands",

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TY - JOUR

T1 - Hydrogen-Related Paramagnetic Centers in Ge-Doped Sol-Gel Silica Induced by γ-Ray Irradiation

AU - Agnello, Simonpietro

AU - Boscaino, Roberto

AU - Magistris, null

AU - Grandi, Stefania

PY - 2006

Y1 - 2006

N2 - We have studied the generation mechanisms of H(II) paramagnetic centers in Ge-doped silica by investigating up to 104 mol ppm sol-gel Ge-doped silica materials. We have considered materials with the same concentrations of Ge but that are produced by two different densification routes that give rise to different concentrations of Ge-related oxygen deficient centers (GeODC(II)). These centers are characterized by an optical absorption band at ∼ 5.2 eV (B2 β band) and two related emissions at ∼ 3.2 eV and ∼ 4.3 eV. The GeODC(II) content was estimated by absorption and emission measurements. The H(II) centers were induced by room temperature γ-ray irradiation and their concentration was determined by electron paramagnetic resonance measurements. The comparison between the two kinds of materials, obtained by different preparations, shows that the GeODC(II) concentration increases with the Ge content and is enhanced by vacuum densification. The comparison of irradiated samples shows that beyond the already known process of conversion of preexisting GeODC(II) into H(II) centers, another generation process of H(II) centers is effective that involves irradiation induced GeODC(II)

AB - We have studied the generation mechanisms of H(II) paramagnetic centers in Ge-doped silica by investigating up to 104 mol ppm sol-gel Ge-doped silica materials. We have considered materials with the same concentrations of Ge but that are produced by two different densification routes that give rise to different concentrations of Ge-related oxygen deficient centers (GeODC(II)). These centers are characterized by an optical absorption band at ∼ 5.2 eV (B2 β band) and two related emissions at ∼ 3.2 eV and ∼ 4.3 eV. The GeODC(II) content was estimated by absorption and emission measurements. The H(II) centers were induced by room temperature γ-ray irradiation and their concentration was determined by electron paramagnetic resonance measurements. The comparison between the two kinds of materials, obtained by different preparations, shows that the GeODC(II) concentration increases with the Ge content and is enhanced by vacuum densification. The comparison of irradiated samples shows that beyond the already known process of conversion of preexisting GeODC(II) into H(II) centers, another generation process of H(II) centers is effective that involves irradiation induced GeODC(II)

UR - http://hdl.handle.net/10447/8979

M3 - Article

VL - 37

SP - 63

EP - 68

JO - Journal of Sol-Gel Science and Technology

JF - Journal of Sol-Gel Science and Technology

SN - 0928-0707

ER -