Structural, ferroelectric and leakage current properties of Bi3.96Pr0.04Ti2.95Nb0.05O12 thin films

Praseodymium and niobium-substituted bismuth titanate (Bi 3.96 Pr 0.04 Ti 2.95 Nb 0.05 O 12 , BPTNO) thin films were deposited on Pt(111)/Ti/SiO 2 /Si(100) substrates by a sol–gel technology. The effects of annealing temperature (500 ~ 800 °C) on microstructure and electric properties of thin films were investigated. X-ray diffraction analysis shows that the BPTNO thin films have a bismuth-layered perovskite structure with preferred (117) orientation. The intensities of (117) peak increases with increasing annealing temperature. With the increase of annealing temperature from 500 °C to 800 °C, the grain size of BPTNO thin films increases. The highly (117)-oriented BPTNO thin films exhibits a high remnant polarization (2 P r ) of 48 μC/cm 2 and a low coercive field (2 E c ) of 110 kV/cm, fatigue free characteristics up to > 10 8 switching cycles. A small leakage current density ( J ) was 6.23 × 10 − 8 A/cm 2 at 200 kV/cm. The leakage current mechanisms were controlled by Poole–Frenkel emission in the low electric field region and by Schottky emission in the high field region.