Effects of film thickness on microstructure and ferroelectric properties of Bi_(3.15)Nd_(0.85)Ti_3O_(12) thin films prepared by sol-gel method

摘要

Bi_(3.15)Nd_(0.85)Ti_3O_(12) (BNT) thin films with different thicknesses (200, 270, 360, 450 and 540 nm) were prepared on Pt/Ti/SiCh/Si substrates by sol-gel method. The effect of film thickness on the microstructure and ferroelectric properties of BNT thin films was investigated. All BNT thin films were consisted of a single phase of bismuth-layered perovskite structure. With increasing film thickness, grains gradually became larger, the remanent polarization (2P_r) firstly increased and then decreased, and the leakage current density showed opposite trend. The 360 nm-thick BNT film exhibited better electrical properties with 2P_r 26 μC/cm~2, coercive field (2E_c) 220 kV/cm, dielectric constant 345 (at 1 MHz) and low leakage current density.