Strontium zinc metaphosphate glasses, xSrO-(50-x)ZnO-50P_2O_5 with x = 0-50 mol% were prepared and studied. The substitution of SrO for ZnO increases density and glass transition temperature (T_g), and enhances the chemical durability of the glasses. The UV-vis spectra of glasses were examined. The optical band gap energies lie in the range of 3.85-4.75 eV and are found to decrease with increasing SrO content. UV transmittance of the glasses at 250 nm is above 70% as SrO content of the glass is lowered to 30 mol%. The structural changes with the glass compositions were examined by FTIR and ~(31)P MAS-NMR spectroscopies. FTIR and ~(31) MAS-NMR spectra indicate that the length of phosphate chain increases with increasing SrO content in the xSrO-(50 - x)ZnO-50P_2O_5 glass system, thus raising T_g and enhancing chemical durability of the glasses.
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