Structure and high dielectric permittivity of Li0.01M0.05Ni0.94O (MÂ =Â V and W) ceramics

Microstructure and dielectric behavior of Li0.01M0.05Ni0.94O (M = V and W) ceramics were studied. The contents of V2O5 and WO3 were mainly dispersed into the grain boundaries and existed as the Ni3V2O8 and NiWO4 phase. The compounds exhibit a negative temperature coefficient of resistance (NTCR) behavior. The dc conductivity of activation energy for the compositions with M = V and W are 0.274 and 0.229 eV. The dielectric constant was decreased toward higher frequencies at room temperature. It is the barrier layer capacitors (BLCs) mechanism and the existing large polarization that can cause the high dielectric constant in Li0.01M0.05Ni0.94O (M = V and W) ceramics.