Study of the influence of Eu doping on dielectric response and specific heat of relaxor ferroelectric Na1/2Bi1/2TiO3.

In this work we present the results of study of the influence of Eu doping on temperature behavior of the dielectric response and conductivity in the frequency range of 10 Hz–1 MHz and the temperature range of 300–750 K, and low temperature (5–400 K) specific heat of the Na1/2Bi1/2TiO3 (NBT) single crystals. It is shown that volume conductivity of NBT is thermally activated with activation energies Ea = 75 meV at T < 320 K and Ea = 700–900 meV at T > 620 K. Eu doping of NBT modifies the behavior of the conductivity with the activation energy being the same at T < 320 K and the deviation of the dependency from Arrhenius law for T > 320 K. Although the comparison of the results of dielectric response experiments for NBT and NBT:Eu3+ reveals significant changes of lattice dynamics induced by Eu doping at T > 320 K, the behavior of the low temperature specific heat remains almost the same. [ABSTRACT FROM AUTHOR]