Ultrasonic characterisation of ferroelectric BaTiO₃ doped lead bismuth oxide semiconducting glasses

Abstract

Ferroelectric BaTiO₃ doped lead bismuth xPbO-(100-x)Bi₂O₃-5BaTiO₃ semiconducting oxide glasses with different PbO contents (x=20,30,40 and 50 wt%) have been prepared by the rapid quenching method. The ultrasonic velocity and attenuation measurements have been made at room temperature (298 K) at frequencies 2.25-10 MHz. From the measured density and ultrasonic velocity data, elastic moduli, Debye temperature, Poisson's ratio and other related physical parameters have been determined. At lower PbO content (PbO<40 wt%), a monotonic decrease in velocity, elastic moduli and Debye temperature was noted. A further increase in PbO content (PbO>40 wt%) lead to an increase in all the above parameters, after showing a minimum at 40 wt% of PbO. In addition, the effect of ultrasonic frequency on velocity and attenuation has also been studied in these glasses. The observed results have been explained in terms of the change in the structure and physical properties of the glass network with change in PbO content.