Effect of substitutions on dielectric behavior of La2NiMnO6

The substituted La₂NiMnO₆ (LNMO) double perovskite powder samples are prepared by hydroxide co-precipitation method. The electrical properties such as conductivity, dielectric constant and impedance analysis of the substituted sample, have been studied. The activation energy is determined by dc conductivity plot gives the fair idea of conduction mechanism. The dielectric and impedance analysis suggests the contribution of extrinsic and intrinsic effects in dielectric relaxation due to substitution at A and B site cations. The Nyquist plot reveals the role of grain and grain boundaries in charge conduction mechanism. The large grain and grain boundary resistance value and activation energy ～100 meV of substituted LNMO samples shows the presence of variable range hopping (VRH) conduction mechanism.