EPR Evidence for Pretransitional Excitations in the Paraelectric Phases of KD2PO4, Nh4H2AsO4, ND4D2AsO4

Abstract

EPR lineshape studies of SeOk3in KD2P04 and CrOk3in NH,HZAsO, and ND,D,AsO, around Tc provide direct evidence of excitations exhibiting the symmetry of the low as well as high temperature phases simultaneously. Critical slowing down from lifetimes s (T > Tc) to -lo-' s (T < Tc) has been established for KD2P04.