Spectroscopic and structural properties of Cr³⁺ ions in lead niobium germanosilicate glasses

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• 作者：T. Narendrudu ; S. Suresh ; G. Chinna Ram ; N. Veeraiah ; D. Krishna Rao ; ^{krdhanekula@yahoo.co.in}
• 关键词：Lead niobium germanosilicate glasses ; Optical absorption ; EPR ; Photoluminescence
• 刊名：Journal of Luminescence
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：183
• 期：Complete
• 页码：17-25
• 全文大小：1171 K
• 卷排序：183

文摘

Glasses of composition PbO–Nb2O5–GeO2–SiO2 doped with different concentrations of Cr2O3 (ranging from 0 to 0.5 mol%) were prepared by conventional melt quenching technique. The prepared glasses were characterized by X-ray diffraction (XRD). Spectroscopic studies viz., optical absorption, EPR, FTIR, Raman and photoluminescence were carried out on these glasses. The optical absorption spectra exhibited three bands at about 646, 674 and 711 nm which are the characteristic bands of octahedral Cr3+ ions. From the analysis of the absorption spectra the crystal field splitting parameters Dq, B and nephelauxetic parameters (β and h) were evaluated. The EPR spectra exhibited two resonance signals at g≈1.97 and g≈4.84. FTIR and Raman spectra have revealed the increasing presence of GeO6 and NbO6 structural units in the glass network with increasing the concentration of Cr2O3 in the glass network. Photoluminescence spectra exhibited a broad emission band in the wavelength region 600 to 850 nm with a meta center at about 680 nm which is also a characteristic of Cr3+ ions. Correlating optical and EPR data the molecular bonding coefficient parameter (α) has been evaluated. The quantitave correlation and analysis of all the results indicated that the glasses doped with higher content of Cr2O3 are efficient luminescence materials.