Giant dielectric response and polarization relaxation mechanism in (Li,V)-doped NiO ceramics

We report the giant dielectric response in (Li,V)-doped NiO (Li0.05V0.02Ni0.93O, Li0.05V0.05Ni0.90 and Li0.05V0.10Ni0.85O) ceramics. Microstructure and phase composition analyses reveal that the ceramics consist of a core/shell structure that is rich in V dopant at the grain boundary. The dielectric response and related electrical properties of these materials are strongly affected by the V content. The giant dielectric behavior of the LVNO ceramics is mainly attributed to the Maxwell–Wagner polarization and thermally activated mechanisms.