Comment on "Ultralow-frequency dispersion in macroscopic susceptibilities"

Abstract

Chaves et al. [Phys. Rev. B 47, 4880 (1993)] have reported an ultralow-frequency dielectric dispersion observed in the ferroelectric phase of KH2PO4 (KDP) crystal as due to the heat-diffusion central-peak contribution. Our temperature dependence study of dielectric relaxations in the same low-frequency region for a natural multidomain KDP crystal confirms that the major part of this low-frequency dielectric dispersion should be attributed not to the heat-diffusion central peak but to the domain wall relaxations as already reported by Paul et al.