Investigation of large dielectric permittivity and relaxation behavior of DyMnO3 single crystal

摘要: We have investigated the frequency-dependent dielectric properties of DyMnO 3 single crystal in the temperature region from 100 K to 320 K. The material shows a large dielectric permittivity in the low-frequency range around room temperature. The dielectric permittivity exhibits a strong temperature dependence at all frequency and two anomalies which can be associated with the Debye-type relaxation with activation energies of 0.66 eV and 0.23 eV in the higher (around 300 K) and lower (around 150 K) temperature regions, respectively. The high value of activation energy around room temperature suggests that the relaxation is associated to the charge carriers hopping resulting from the second ionization of oxygen vacancies. However, the impedance analysis suggests that the low-temperature relaxation is due to the Maxwell–Wagner type effects originating from the dipoles at the surface.