Thickness dependence of the nucleation field of triglycine sulphate

Abstract The applied electric field at the onset of polarization reversal during switching of a triglycine sulphate single crystal with a sinusoidal applied field has been measured as a function of crystal thickness. In contrast to the sinusoidal coercive field measurements of Pulvari and Kuebler (1958), this field is frequency independent and thickness dependent according to the relation En α (thickness)−2/3. The results are discussed as a nucleation phenomenon on the basis of a simple model and lead to an estimate of the domain wall surface energy of triglycine sulphate as being of the order of 1 erg/cm2. Finally a criticism of the theory is discussed.