Anomalous heat conduction in ferroelectric crystals with incommensurate phases

Abstract

The results of thermal conductivity measurements for two ferroelectric crystals, (NR4)(2)BeF4 and Rb2ZnCl4, with incommensurate phases are presented. It is found that anomalies exist in the thermal conductivities of these crystals in the incommensurate phases. The incommensurate modulation waves cause these anomalies in the heat-transport processes by the scattering of heat carrying phonons rather than by their direct participation as heat carriers.