Elastic properties of lanthanum gallogermanate glasses

Room temperature ultrasonic velocities of eight lanthanum gallogermanate gl asses were determined by pulse-echo technique. The results indicate that bo th longitudinal and transverse velocities of these glasses are composition dependent. The density and index of refraction of the samples were also stu died. The experimental results were used to obtain elastic constants. The m easured values of Young's modulus and bulk modulus for our glasses show goo d agreement with the theoretically calculated results based on the model of Makishima and Mackenzie. (C) 1999 Kluwer Academic Publishers.