Dielectric and mechanical loss and mobility of domain walls

Abstract

Three dielectric loss (D) and /or three mechanical loss (Q⁻¹) peaks (P₁, P₂, P₃) for KDP, TGS and LNPP (La₁-xNd_xPsO₁₄) crystals have been investigated. P₁ is attributed to the dynamic domains due to the fluctuation near Tc. P₂ is related to domain walls (DWs). The Q⁻¹ and D caused by the viscous motion of DWs are calculated, being fairly coincident with the experimental data of P₂ peak in the kHz range. P₃ peak drops down to zero rapidly in the low temperature side for TGS, and disappears in LATGS with mono-domain. So P₃ is thought to originate from glass transition of pinned domain walls.