X-ray induced absorption in fused silica containing various amounts of OH

Abstract

Characteristics of x-ray-induced absorption spectra in various types of synthetic fused silica ͑SFS͒ containing 0.1-77ϫ 10 18 cm −3 of OH were studied up to an irradiation time of 6 h. Induced absorption in the SFS spectra of irradiation with x ray from a Rh target with a dosage of 2 ϫ 10 4 C kg −1 h −1 was reproduced by six Gaussian absorption bands, at 3.8, 4.8, 5.0, 5.4, 5.8, and 6.5 eV, respectively. Intensities of these absorption bands increased with power of irradiation time. The intensities of the 5.8, 5.4, and 5.0 eV bands decreased with increasing OH content at an irradiation time shorter than 2 h. At an irradiation time longer than 2 h, on the other hand, the intensities of each absorption band had a minimum at an OH content of Ϸ5 ϫ 10 18 cm −3

Systematic investigation of composition effects on the radiation-induced attenuation mechanisms of aluminosilicate, Yb-doped silicate, Yb- and Yb,Ce-doped aluminosilicate fiber preforms [Invited]

“…Centers at 5.75-5.83 eV and full width at half maximum (FWHM) of 0.62-1.05 eV have been indeed widely admitted for the OA band of SiE' centers [13,[22][23][24]. The NBOHC band at 4.8 eV (FWHM = 1.05 eV) has similar characteristics as usually reported ones (center at 4.75-4.9 eV and width of 1.05 eV [13,[22][23][24]). We also attributed the 6.82 eV band (FWHM = 1.29 eV) to NBOHCs, following the proposal by Hosono et al that NBOHCs also absorb at 6.8 eV (FWHM = 1.76 eV) [25].…”

“…We nevertheless note that the OA band of SiE' centers is slightly red-shifted down to 5.5 eV (about 5% below its usual location around 5.8 eV). This shift could be due to an enhanced contribution of a SiE' center variant in this sample, namely SiE'-β centers that have an OA band at 5.41 eV (FWHM = 0.62 eV) [23]. The consequence is that the width of the NBOHC band at 4.8 eV is reduced to 0.8 eV instead of 1.05 eV (see [13,[22][23][24] and Fig.…”

“…Gaussian components can be assigned to the so-called SiE' and Non-Bridging Oxygen Hole Centers (NBOHCs) [13][14][15]. Centers at 5.75-5.83 eV and full width at half maximum (FWHM) of 0.62-1.05 eV have been indeed widely admitted for the OA band of SiE' centers [13,[22][23][24]. The NBOHC band at 4.8 eV (FWHM = 1.05 eV) has similar characteristics as usually reported ones (center at 4.75-4.9 eV and width of 1.05 eV [13,[22][23][24]).…”

Silicon Nanocluster in Silicon Dioxide: Cathodoluminescence, Energy Dispersive X-Ray Analysis and Infrared Spectroscopy Studies

“…Experiments had suggested that the ≡Si−O−H is resisting bond breakage effectively at relatively short irradiation time. Bond breakage might saturate only at sufficiently long irradiation time [Kuzuu and Horikoshi 2005]. Different properties are shown by the wet oxide in Fig.3.8.…”

“…The ≡Si−O−H bond is a good candidate to form NBOHC at room temperature in hydrogen rich silica. The NBOHC is possibly produced by breaking the H bonds at high annealing temperatures (T a >1000°C) or under electron irradiation [Kuzuu and Horikoshi 2005]. Direct hydrogen implantation or H 2 O molecule formation on the surface or in the silica network are believed to be the main reasonable source of the Y luminescence [Fitting et al 2005b]; that means there are two aspects for the origin of this band.…”