Effect of Ni-doping charge on structure and properties of LiNbO3

Phase formation and structural properties of ni-doped li0.976-xnb1.005-x/5nixo3 (0 ≤ x ≤ 0.1) ceramics prepared by solid-state reaction method,are investigated in a temperature range from 400 to 900 °c. x-ray diffraction patterns indicate that single phase was formed for lithium niobate ceramics. it was shown that the unit-cell volume of the hexagonal phase decreased with increasing nickel concentration from 0 to 3% ni charge and increased above 3%. no secondary phases were observed in ni-doped powder of linbo3 for all concentrations compared with that of undoped sample. these results indicate that the ni2+ ion was substituted for niobium and lithium ions in the hexagonal phase. the addition of ni2+ promotes densification of lithium niobate ceramics. raman spectra show that the samples were well crystallized with high purity. it was noticed that the increase of ni-doping causes the decreasing of resistivity at high temperatures,but it has no influence of activation energy.