Mechanism of domain freezing in KDP type ferroelectrics

Abstract
The dielectric relaxation time τ of KH2PO4 and CsH2AsO4 was investigated in the ferroelectric phase through measurements of the complex dielectric constants in the frequency range between 103 Hz and 109 Hz. Anomalous increase in τ near the domain freezing temperature Tf , considered together with the relation between the free dielectric constant εc and the the elastic stiffness C 66 E , suggests that dipolar reorientation in the domain walls has a close relation to the hardening of the crystal around Tf , which originates the domain freezing.