# Low-Temperature Characterization of Domain Wall Dynamics and Electrical Conduction in a Proton-Irradiated K(H0.21D0.79)2PO4 System

• Lee, Cheol Eui (Department of Physics, Korea University) ;
• Oh, Byoung Hoo (Department of Physics, Korea University) ;
• Kim, Se-Hun (Faculty of Science Education and Educational Science Research Institute, Jeju National University)
We investigated the longitudinal electrical conductivity associated with the domain-wall dynamics in proton-irradiated $K(H_{0.21}D_{0.79})_2PO_4$ single crystals a temperatures below room temperature. Frequency-dependent longitudinal dielectric-loss measurements allowed us to investigate the changes in the domain-wall dynamics of the proton-irradiated crystal with a ferroelectric phase-transition temperature increase of 8 K. Using the Vogel-Fulcher function, we found that proton irradiation produced a slight increase in the activation energy of domain freezing. The temperature dependence of the power-law exponent n in frequency-dependent electrical conductivity in proton-conducting systems decreased at temperatures near the phase-transition temperature $T_{c2}$. In addition, the temperature dependence of the electrical conductivity shifted to higher temperatures because of the increased phase-transition temperature arising from the proton irradiation.