Dielectric relaxation and ac conductivity study in SrMg1/3Nb2/3O3

The frequency-dependent dielectric dispersion of strontium-magnesium-niobate, SrMg1/3Nb2/3O3 ceramic synthesized by the solid state reaction technique is investigated in the temperature range from room temperature to 613 K. The X-ray diffraction of the sample at room temperature shows monoclinic phase. An analysis of the real and imaginary parts of impedance is performed, assuming a distribution of relaxation times as confirmed by Cole-Cole plot as well as the scaling behaviour of the imaginary part of impedance spectra. The frequency dependent electrical data were analyzed in the framework of the conductivity and modulus formalisms. The activation energy of the non-Debye process evaluated from the modulus formalism resembles with energy activation evaluated for the current conductivity process, indicating the similar nature of relaxation and conductivity.