Radiation-damage-induced defects in quartz. I. Single-crystal W-band EPR study of hole centers in an electron-irradiated quartz

Nilges, Mark J.; Pan, Yuanming; Mashkovtsev, R. I.

doi:10.1007/s00269-007-0203-5

Cited by 45 publications

(19 citation statements)

References 44 publications

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“…By analogy to kaolinite, it may correspond to an electron hole on an oxygen atom in the vicinity of a heterovalent substitution (e.g., Mg 2+ ). By analogy to quartz, it may consist as well in spin trapping on di-or tri-oxygen species near a Si vacancy (see e.g., Nilges et al 2008;Pan and Hu 2009). Only isothermal data can provide useful and relevant values of parameters such as half-life and activation energy.…”

Section: Introductionmentioning

confidence: 98%

The thermal stability of radiation-induced defects in illite

et al. 2015

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Section: Introductionmentioning

confidence: 98%

The thermal stability of radiation-induced defects in illite

et al. 2015

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“…The effective g values of all detected signals are shown in the experimental spectrum in Figure 7, which shows spectra of separated macro-crystalline quartz and chalcedony parts of the agate from St. Egidien (AStE). The broad peak at g = 2.034 arises from superoxide centers (O 2 -) B and B′, while the signal at g = 2.017 belongs to several ozonide C (and C′) radicals (O 3 -; Botis et al 2008;Nilges et al 2008Nilges et al , 2009Pan et al 2008). The small signal at g = 2.021, which has a microwavepower dependence different from hole centers but is similar to those of E′ centers, is most likely related to the g = 1.983 line and corresponds to a new E′/H center (g // = 2.0020 and g^ = 2.010) with a proton hyperfine structure (A // = 6.4 mT and A^ = 6.7 mT), which has been observed from single-crystal EPR data (Mashkovtsev pers.…”

Section: Cathodoluminescence (Cl)mentioning

confidence: 96%

Origin and significance of the yellow cathodoluminescence (CL) of quartz

Götze

Pan

Stevens‐Kalceff

et al. 2015

American Mineralogist

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The origin of yellow cathodoluminescence (CL) in quartz has been investigated by a combination of CL microscopy and spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, and spatially resolved trace-element analysis by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The study shows that the appearance of a ~570 nm (2.17 eV) emission band can be attributed to high oxygen deficiency and local structural disorder in quartz. A proposed luminescence center model implies self-trapped exciton (STE) emission from localized amorphized regions in quartz. Although the high-intensity emission at 570 nm is in general consistent with high concentrations of E′ 1 defects detected by EPR spectroscopy, CL studies with different electron beam parameters and annealing experiments up to 600 °C show a temperature and irradiation dependence of the luminescence related defects excluding the role of E′ 1 centers as direct luminescence activators for the 570 nm emission. The evaluation of geochemical data shows that quartz with yellow CL occurs in low-temperature hydrothermal environment (mostly <250 °C) and is related to fast crystallization in an environment with oxygen deficiency.

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“…Again, all spectra have low signal-to-noise ratios. Indeed, none of the radiation-induced defects at the effective g values of ~2.00 are present [16][17][18][19]. Even the common E'1 is exceedingly rare.…”

Section: Electron Paramegnetic Resonance (Epr)mentioning

confidence: 99%

Trace Element Compositions and Defect Structures of High-Purity Quartz from the Southern Ural Region, Russia

et al. 2017

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Abstract:Quartz samples of different origin from 10 localities in the Southern Ural region, Russia have been investigated to characterize their trace element compositions and defect structures. The analytical combination of cathodoluminescence (CL) microscopy and spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, and trace-element analysis by inductively coupled plasma mass spectrometry (ICP-MS) revealed that almost all investigated quartz samples showed very low concentrations of trace elements (cumulative concentrations of <50 ppm with <30 ppm Al and <10 ppm Ti) and low abundances of paramagnetic defects, defining them economically as "high-purity" quartz (HPQ) suitable for high-tech applications. EPR and CL data confirmed the low abundances of substitutional Ti and Fe, and showed Al to be the only significant trace element structurally bound in the investigated quartz samples. CL microscopy revealed a heterogeneous distribution of luminescence centres (i.e., luminescence active trace elements such as Al) as well as features of deformation and recrystallization. It is suggested that healing of defects due to deformation-related recrystallization and reorganization processes of the quartz lattice during retrograde metamorphism resulted in low concentrations of CL activator and other trace elements or vacancies, and thus are the main driving processes for the formation of HPQ deposits in the investigated area.

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Radiation-damage-induced defects in quartz. I. Single-crystal W-band EPR study of hole centers in an electron-irradiated quartz

Cited by 45 publications

References 44 publications

The thermal stability of radiation-induced defects in illite

The thermal stability of radiation-induced defects in illite

Origin and significance of the yellow cathodoluminescence (CL) of quartz

Trace Element Compositions and Defect Structures of High-Purity Quartz from the Southern Ural Region, Russia

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