Ferroelectric properties of vanadium-doped Bi4Ti3O12 thin films deposited by a sol–gel method

We report the enhancement of ferroelectric properties in vanadium-doped Bi4Ti3O12 (BIT) thin films deposited by a sol–gel method. Compared to the undoped BIT, V-doped BIT (BTV) showed higher polarizations and a better fatigue resistance as reported in ceramic systems recently [Noguchi et al., Appl. Phys. Lett. 78, 1903 (2001)]. BTV showed a remanent polarization (2Pr) of 15.9 μC/cm2, higher than the value for BIT, 12.5 μC/cm2. The polarization of the BTV thin film capacitor decreased by 19%, while that of the BIT decreased by 23% after the fatigue test with 4×1010 switching cycles.