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Borate and borosilicate glasses with compositions of xZnO–2xPbO–(1−3x)B2O3 and xZnO–2xPbO–1/2(1−3x)B2O3–1/2(1−3x)SiO2 with x varying from 0.1 to 0.26 mole fraction were prepared by the conventional melt quench technique. Optical and structural properties have been determined by using ultraviolet–visible (UV/vis) and Fourier transform infrared (FTIR) spectroscopic techniques. Decreases in the band gap from 3.57 to 2.62 eV for borate glasses and from 3.00 to 2.35 eV for borosilicate glasses with an increase in the metal oxide content is observed. The density and molar volume has also been measured. Increases in density from 3.994 to 6.339 g cm−3 for borate and from 4.221 to 6.548 g cm−3 for borosilicate glasses are observed with an increase in metal oxide (PbO, ZnO or PbO+ZnO) content. Changes in the atomic structure with composition are observed due to the formation of BO4− units.

The effect of gamma irradiation has been probed by transmission measurements before and after γ‐irradiation on lead borate and bismuth borate glasses of varying composition by exposing with 60Co radioisotope of absorbed dose 2.5 kGy. The induced absorption coefficient, effect of irradiation on optical band gap, width of tail and cut off wavelength are discussed by taking into account the possible dependence of radiation hardness on composition and defects produced in a glass matrix. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Acoustic and structural properties of x CaO · (1–x ) B2O3 (0.2 ≤ x ≥ 0.7) glass system have been studied at ambient temperature. The ultrasonic velocity and attenuation for different compositions of calcium borate glasses were measured at 5 MHz at room temperature (303 K) using a pulse echo overlap method. The elastic moduli, Debye temperature, Poisson's ratio and other acoustic parameters have been obtained from experimental data. Fourier transform infrared spectroscopic analysis has been used to further support the results of acoustic studies. The results obtained indicate that the calcium oxide enters the glass network as a modifier by occupying the interstitial spaces in the network and by increasing the nonbridging oxygen atoms (NBOs). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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