EPR, optical and physical properties of chromium ions in CdO-SrO-B₂O₃-SiO₂ (CdSBSi) glasses

详细信息    查看全文

• 作者：J. Santhan Kumar^a ; J. Lakshmi Kumari^a ; ^b ; M. Subba Rao^a ; Sandhya Cole^a ; ^{sandhya.cole@gmail.com}
• 关键词：Borosilicate glass ; EPR ; Optical absorption ; Cr3+ ion ; FT-IR ; Powder XRD
• 刊名：Optical Materials
• 出版年：2013
• 出版时间：May, 2013
• 年：2013
• 卷：35
• 期：7
• 页码：1320-1326
• 全文大小：1376 K

文摘

Chromium ions doped 10CdO-(20?x) SrO-50B₂O₃-20SiO₂ (x = 0.5, 1.0, 1.5, 2.0, 2.5 mol % ) (CdSBSi) glasses have been studied by using Electron Paramagnetic Resonance (EPR) and optical absorption techniques at room temperature. Powder XRD pattern of all the samples confirms amorphous nature of the glass. The low field spectral line of the EPR spectrum of chromium ions in CdSBSi glass is attributed to isolated Cr³⁺ ions and the high field spectral line is assigned for exchange of coupled pairs Cr³⁺ ions in all these glasses. The optical absorption spectra of Cr³⁺ ions in these glasses shows single broad band characteristic of Cr³⁺ ions in near octahedral symmetry. From this optical absorption spectral data the crystal field parameter (Dq) is evaluated from ultraviolet absorption edges, the optical band gap and Urbach energies are evaluated. The results assert that the optical band gap energy values are depended quite sensitively on added chromium content. The FT-IR spectral investigations of chromium ion doped glasses exhibits characteristic vibrations of BO₃ units. Several physical parameters are also evaluated for these glasses with respect to the composition.