Investigations of lithium-chloro-borate glass-ceramic and its elastic properties

Abstract

Elastic properties and microstructural studies of 0.3Li2O-0.2LiCl-0.5B2O3 glass-ceramics have been carried out for a precursor glass prepared using the rapid melt quenching technique. Quenched glasses were heat treated (by three step process) at 150 °C for 2, 4, 6, and 8 h. Scanning electron microscopy and X-ray diffraction studies clearly indicate gradual growth of different phases in the glass matrix with increasing time of heat-treatment. IR studies reveal the structural modification in the network as the precursor glass transformed into glass-ceramic. Elastic properties have been measured by performing ultrasonic wave velocity measurements at a frequency of 10 MHz. Longitudinal and shear moduli of the samples tend to increase with heat-treatment time. However, the bulk modulus is almost insensitive to heat treatment. The Debye temperature was found to increase, and the Poisson ratio lies in the range 0.2–0.3 (typical for covalently bonded networks) with an increase in heat-treatment time.