ions doped zinc bismuth borate glasses

Glasses having composition 20ZnO·xBi2O3·(79-x)B2O3 (15 x 35, in mol%) doped with 1 mol% of Nd 3+ ions were prepared. The different physical and absorption spectral properties have been investigated to understand the variation of the hypersensitive absorption band intensities. From the absorption spectra, Judd-Ofelt intensity parameters, ( = 2, 4, 6) have been calculated and these parameters were used to estimate the radiative properties. The values of Judd-Ofelt parameters increase with increase in the concentration of Bi2O3, which may be due to the increase in neodymium-oxygen (Nd-O) covalency. The glass having high bismuth content has displayed a significant increase in the intensity of the hypersensitive transition 4G5/2+ 2G7/2 4I9/2 of Nd 3+ ion which may be attributed to the asymmetry ligand field around the rare earth ion site. The shifting of the hypersensitive band shows that the covalency of the rare earth (RE-O) bond increases with Bi2O3 content in the glass due to increased interaction between the rare earth ion and the non-bridging oxygen. The large radiative transition probabilities in the present glasses suggest their suitability for various laser applications. The structure of the present glasses has been studied using FTIR spectroscopy.