Improved Electrical Properties of Layer Structured La 2 Ti 1.96 V 0.04 O 7 Ceramics

La2Ti1.96V0.04O7 (LTVO) ceramics with Ti4+ ions partially substituted by V5+ ions at B sites show excellent electrical properties. The dopant V5+ ions do not result in collapse of the cell layered structure, but they lead to the enhanced distortions of BO6 oxygen octahedrons. Impedance spectroscopy reveals that a certain number of defects are formed due to the substitution of Ti4+ ions by V5+ ions. Meanwhile, the concentration of oxygen vacancies is decreased compared to pure La2Ti2O7 (LTO) ceramics. The direct current resistivity of LTVO ceramics obtained from alternating current (AC) impedance fitting at 600°C is 1.3 × 106 Ω cm, which is more than five times of that of the pure LTO at the same temperature (2.2 × 105 Ω cm). The substitution of Ti4+ ions by V5+ ions greatly enhances the piezoelectric coefficient, d33 = 4.8 pC/N. Therefore, the doping of V5+ ions in the B sites of LTO ceramics should be a good choice for enhancing their piezoelectric properties and resistivity at high temperature regimes.