Influences of Mass and Bond Length on the Debye Temperatures of Ionic and Covalent Substances

A survey of the literature demonstrated that the known Debye temperatures of alkali halides form a linear function of 1/√m̄r 0 3 through the origin, where r 0 is the nearest-neighbor distance and m̄ is the averaged mass. The known Debye temperatures of isostructural covalent substances, and especially those of diamond, silicon, germanium and grey tin, fall on a straight line versus 1/√m̄r 0 4 through the origin. The Debye temperatures of the alkali halides and alkaline-earth oxides with the rock salt structure are appropriately evaluated on a simple model from their elastic stiffness constants.