Role of grain boundary in transport properties of LiCo3/5Mn2/5VO4 ceramics

Electrical properties of LiCo3/5Mn2/5VO4 are investigated using ac technique of complex impedance spectroscopy (CIS). Microstructure study of the sintered pellet reveals grains of unequal sizes (∼0.2−2 μm). Grain interior, grain boundary and electrode-material interface contributions to electrical response are identified by the analysis of complex plane diagrams. Variation of d.c. conductivity (σdc) with temperature indicates that the electrical conduction in the material is a thermally activated process. The value of activation energy computed from the Arrhenius plot of σdc and σgb with 103/T are ∼ (0.409±0.015) eV (27−275 °C) and ∼ (0.429±0.029) eV (27−275 °C), respectively. The scaling behavior of imaginary electric modulus shows the non-Debye type (polydispersive) conductivity relaxation in the material.