Quadratischer elektrostriktiver Tensor des rhombischen Calciumformiats

Abstract

Abstract All twelve independent components dijkl = ½[unk](εij components of strain tensor, Ek components of electric field) of the quadratic electrostrictive tensor of rhombic calcium formate have been determined employing an improved method for measuring extremely small thickness variations. These variations are transformed into a frequency modulation of a 100 MHz oscillator and compensated with the aid of an auxiliary crystal of known linear electrostriction. The constants exhibit a similar behaviour as those of alkali halides of rocksalt type: the response on an electric field is a longitudinal contraction and a transversal dilatation. The observed distinct anisotropy is correlated with the elastic and dielectric behaviour.