Effective elastic module of chalcogenide glasses

The product of the density of a solid body per the square of the average quadratic speed of deformation waves, which has characteristic specific for elastic modules, is called the effective modulus of elasticity. It is shown that for oxygen-free chalcogenide glasses, the ratio of the volume compression modulus to the effective elastic modulus is an unambiguous function of the Poisson's ratoi, as for oxide glasses. The effective modulus of elasticity is closely related to the Grueneisen parameter, which serves as a measure of anharmonism. The nature of the relationship between harmonic (linear) and anharmonic (nonlinear) values is discussed on the basis of a unique relationship between the Poisson coefficient and the Grueneisen parameter.