Study of defects in implanted silica glass by depth profiling Positron Annihilation Spectroscopy

Brusa, R. S.; Mariazzi, S.; Ravelli, L.; Mazzoldi, P.; Mattei, Giovanni; Egger, Werner; Hugenschmidt, C.; Löwe, Benjamin; Pikart, Philip; Macchi, C.; Somoza, A.

doi:10.1016/j.nimb.2010.05.084

Cited by 11 publications

(5 citation statements)

References 23 publications

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“…The average diameter of interstitial voids in silica glass is estimated as ≈5 Å from positron annihilation studies [33]. Similar size voids develop in αquartz on n-irradiation of fluences > 10 19 n/cm 2 [34] or after ion implantation [35]. In the case of e − − irradiation of α-quartz it has been observed that disordered ("metamict") inclusions (diameter ≈10 nm at dose 10 GGy) initially grow heterogeneously, at irregula-rities of the crystal structure, most likely at precursor sites: hydroxyl impurities or dislocations [36].…”

Section: Oxygen Dangling Bondsmentioning

confidence: 99%

Creation of glass-characteristic point defects in crystalline SiO2 by 2.5 MeV electrons and by fast neutrons

Skuja

Ollier

Kajihara

et al. 2019

Journal of Non-Crystalline Solids

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Point defects in crystalline SiO2, created by 2.5 MeV electron irradiation at dose below the amorphization threshold or by fast neutrons, were compared by luminescence spectroscopy. Oxygen dangling bonds ("non-bridging oxygen hole centers", NBOHCs), peculiar to amorphous state of SiO2, were detected for the first time in electron-irradiated non-amorphized αquartz crystal. Their presence may signal the formation of nucleation centers in crystal structure as the first step to radiationinduced amorphization. Compared to crystal, irradiated by 10 19 cm −2 fast neutrons, their concentration was over 100 times lower, and their inhomogeneous broadening was at least 2.5 times smaller. Divalent silicons ("silicon oxygen deficiency centers", SiODC(II)), inherent to oxygen-deficient or irradiated SiO2 glass, were detected in neutron-irradiated (10 19 n/cm 2) α-quartz but were not found after the electron irradiation. Radiation-induced interstitial O2 molecules, characteristic to irradiated glassy SiO2 and other oxide glasses, are found in α-quartz only after neutron irradiation. The oxygen atoms, displaced by the 2.5 MeV e − irradiation of α-quartz for fluences up to 10 19 e − /cm 2 evidently stays entirely in the peroxy linkage (Si-O-O-Si bond) form.

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Section: Oxygen Dangling Bondsmentioning

confidence: 99%

Creation of glass-characteristic point defects in crystalline SiO2 by 2.5 MeV electrons and by fast neutrons

Skuja

Ollier

Kajihara

et al. 2019

Journal of Non-Crystalline Solids

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“…[18]), and imaging of the spatial variation of the oxygen deficiency, and hence the local variation of the transition temperature for superconductivity, in single crystalline YBa 2 Cu 3 O 7−δ thin films [19], (iii) in polymer films, the determination of the free volume [20] and the open volume in bioadhesive [21], (iv) thin film annealing and alloying at a Au/Cu interface [22] as well as interdiffusion in epitaxial single-crystalline Au/Ag thin films [23], (v) irradiation induced defects e.g. in Mg [24] and in silica [25,26] as well as defect annealing after He implantation in InN and GaN [27] and H induced defects in Pd films [28], (vi) defect imaging of the fatigue damage in Cu [29], around a scratch on a GaAs sample [30], and in Al samples after plastic deformation [31]. For further details of near-surface studies with positron refer to appropriate reviews (see e.g.…”

Section: Introductionmentioning

confidence: 99%

Positrons in surface physics

Hugenschmidt¹

2016

Surface Science Reports

127

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Within the last decade powerful methods have been developed to study surfaces using bright low-energy positron beams. These novel analysis tools exploit the unique properties of positron interaction with surfaces, which comprise the absence of exchange interaction, repulsive crystal potential and positron trapping in delocalized surface states at low energies. By applying reflection highenergy positron diffraction (RHEPD) one can benefit from the phenomenon of total reflection below a critical angle that is not present in electron surface diffraction. Therefore, RHEPD allows the determination of the atom positions of (reconstructed) surfaces with outstanding accuracy. The main advantages of positron annihilation induced Auger-electron spectroscopy (PAES) are the missing secondary electron background in the energy region of Auger-transitions and its topmost layer sensitivity for elemental analysis. In order to enable the investigation of the electron polarization at surfaces low-energy spin-polarized positrons are used to probe the outermost electrons of the surface. Furthermore, in fundamental research the preparation of well defined surfaces tailored for the production of bound leptonic systems plays an outstanding role. In this report, it is envisaged to cover both, the fundamental aspects of positron surface interaction and the present status of surface studies using modern positron beam techniques.

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“…The coincident count rate in the photo-peak amounted to 300 s À1 ; the total coincident counts in the photopeak were about 10 million. The Doppler energy shift is DE ¼ jE c À 511 keVj , where Ec is the energy of the detected annihilation photon, which is related to the component of the electron-positron momentum component along the photon direction p L by the relation p L ¼ 2DE=c [34]. The DB spectra of the annihilation peak are recorded as a function of the positron implantation energy.…”

Section: Fe12crmentioning

confidence: 99%

Characterization of ion-irradiated ODS Fe–Cr alloys by doppler broadening spectroscopy using a positron beam

Parente

Castro

Gigl

et al. 2015

Journal of Nuclear Materials

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a b s t r a c tThe damage profile of oxide dispersion strengthened steels after single-, or simultaneous triple-ion irradiation at different conditions has been characterized using a low energy positron beam in order to provide information on microstructural changes induced by irradiation. Doppler broadening and coincident Doppler broadening measurements of the positron annihilation line have been performed on different Fe-Cr-(W,Ti) alloys reinforced with Y 2 O 3 , to identify the nature and stability of irradiation-induced open-volume defects and their possible association with the oxide nanoparticles. It was found that irradiation induced vacancy clusters are associated with Cr atoms. The results are of highest interest for modeling the damage induced by 14 MeV neutrons in reduced activation Fe-Cr alloys relevant for fusion devices.

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Study of defects in implanted silica glass by depth profiling Positron Annihilation Spectroscopy

Cited by 11 publications

References 23 publications

Creation of glass-characteristic point defects in crystalline SiO2 by 2.5 MeV electrons and by fast neutrons

Creation of glass-characteristic point defects in crystalline SiO2 by 2.5 MeV electrons and by fast neutrons

Positrons in surface physics

Characterization of ion-irradiated ODS Fe–Cr alloys by doppler broadening spectroscopy using a positron beam

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Study of defects in implanted silica glass by depth profiling Positron Annihilation Spectroscopy

Cited by 11 publications

References 23 publications

Creation of glass-characteristic point defects in crystalline SiO2 by 2.5 MeV electrons and by fast neutrons

Creation of glass-characteristic point defects in crystalline SiO2 by 2.5 MeV electrons and by fast neutrons

Positrons in surface physics

Characterization of ion-irradiated ODS Fe–Cr alloys by doppler broadening spectroscopy using a positron beam

Contact Info

Product

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Creation of glass-characteristic point defects in crystalline SiO2 by 2.5 MeV electrons and by fast neutrons

Creation of glass-characteristic point defects in crystalline SiO2 by 2.5 MeV electrons and by fast neutrons