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

摘要

Elastic properties and microstructural studies of 0.3Li(2)O-0.2LiCl-0.5B(2)O(3) 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 degrees 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.