Leakage current characteristics of Bi3.15Nd0.85Ti3 − xZrxO12 thin films

Thin films of Bi3.15Nd0.85Ti3O12 (BNT) and Bi3.15Nd0.85Ti3 − xZrxO12 (BNTZx, x = 0.1 and 0.2) were fabricated on Pt/TiO2/SiO2/Si(100) substrates by a chemical solution deposition (CSD) technique at 700 °C. Structures, surface morphologies, leakage current characteristics and Curie temperature of the films were studied as a function of Zr ion content by X-ray diffraction, atomic force microscopy, ferroelectric test system and thermal analysis, respectively. Experimental results indicate that Zr ion substitution in the BNT film markedly decreases the leakage current of the film, while almost not changing the Curie temperature of the film, which is at about 420–460 °C. The decrease of the leakage current in BNTZx films is that the conduction by the electron hopping between Ti4+ and Ti3+ ions is depressed because Zr4+ ions can block the path between two adjacent Ti ions and enlarge hopping distance.