Dielectric constant of KDP at ultra low frequencies

Abstract

As reported by Adriaenssens and Bjorkstam1 KH2AsO4 (KDA) shows a low-frequency dielectric relaxation in a narrow region above the transition temperature. Though the relaxation may be explained by the existence of a central mode other possible origins can not be excluded. A similar relaxation of the dielectric constant was assumed to exist in KH2PO4 (KDP) for frequencies below 1 kHz but it could not be analysed by a radio frequency bridge.