Elastic and Structural Properties of Potassium and Calcium – Doped Borate Lithium Glasses

Glass sample of the system, B2O3-Li2O containing different concentration of potassium oxide and calcium oxide ranging from 0 to 10 mol% were prepared by the melt quenching method. Structure that was investigated using X-ray diffraction has indicated the amorphous state of the prepared glasses. Elastic properties of the glasses were studied by measuring the ultrasonic velocities (both longitudinal and shear velocities) and attenuation using the pulse-echo method. Measurements were carried out 2MHZ frequency at room temperature. The density of all the prepared glasses was measured using Archimedes principle. A decrease in density and increase in molar volume with increasing of K2O and CaO content reveals that the formation of non-bridging oxygen (NBO) in the structural network. Elastic moduli, Poisson’s ratio, acoustic impedance, Debye temperature, internal friction, microhardness and thermal expansion coefficient have been calculated using ultrasonic velocities, attenuation and density measurements. Furthermore, these results are interpreted in terms of the change in the topology of these glass structures. The elastic moduli are observed to decrease with the increase of K2O and CaO content due to the decreased fractal bond connectivity