Improved Electrical Properties of Layer Structured La2Ti1.96V0.04O7 Ceramics

La 2 Ti 1.96 V 0.04 O 7 (LTVO) ceramics with Ti 4+ ions partially substituted by V 5+ ions at B sites show excellent electrical properties. The dopant V 5+ ions do not result in collapse of the cell layered structure, but they lead to the enhanced distortions of BO 6 oxygen octahedrons. Impedance spectroscopy reveals that a certain number of defects are formed due to the substitution of Ti 4+ ions by V 5+ ions. Meanwhile, the concentration of oxygen vacancies is decreased compared to pure La 2 Ti 2 O 7 (LTO) ceramics. The direct current resistivity of LTVO ceramics obtained from alternating current (AC) impedance fitting at 600°C is 1.3 × 10 6 Ω cm, which is more than five times of that of the pure LTO at the same temperature (2.2 × 10 5 Ω cm). The substitution of Ti 4+ ions by V 5+ ions greatly enhances the piezoelectric coefficient, d 33 = 4.8 pC/N. Therefore, the doping of V 5+ ions in the B sites of LTO ceramics should be a good choice for enhancing their piezoelectric properties and resistivity at high temperature regimes.