Ferroelectric domain freezing and charge conduction in proton-irradiated K(H_0.36D_0.64)₂PO₄

We have studied the effects of proton irradiation in K(H_0.36D_0.64)₂PO₄ single crystals by employing impedance spectroscopy. Frequency-dependent dielectric loss measurements allowed us to investigate changes in the domain wall dynamics of a proton-irradiated crystal with a ferroelectric phase transition temperature raised by 5 K. Thus, the increase caused by proton irradiation in the activation energy of the domain freezing in the direction of the hydrogen bonds was found to be significantly greater than in the case of KH₂PO₄. Furthermore, the temperature dependence of the power-law exponent n in the frequency-dependent electrical conductivity in the proton-conducting systems manifested changes arising from the proton irradiation in the interactions between the mobile ionic (proton) charges and their environments.