Acoustic-mode contributions to pyroelectric compliance

Abstract

A recently developed thesis by Grout, March and Thorp (see ibid., vol.8, p.2167 (1975)) that acoustic-mode or 'Born-function' contributions to the pyroelectric compliance p are a dominant feature of strong pyroelectricity is challenged. Weaknesses in the argument are stressed and evidence is presented that, for at least one example, namely LiTaO₃, acoustic contributions are barely measurable, contributing a maximum of 2.5*10^-5 mu C cm^-2 K^-1 to p, an amount which is only of the order of 0.1% of the total pyroelectric compliance of LiTaO₃ at room temperature.