Structural, Ferroelectric, Dielectric Properties and Leakage Characteristics of Neodymium-Doped Bi₄Ti₃O₁₂ Thin Films Prepared by Metalorganic Deposition Method

Thin films of Nd³⁺-substituted Bi_3.15Nd_0.85Ti₃O₁₂ (BNT) were fabricated on the (111 Pt/TiO₂/SiO₂/Si substrates by a metalorganic deposition (MOD) technique. These thin films are possessed of a single-phase bismuth-layered structure showing the preferred (001) and (117) orientation. The values of the remanent polarization P_r and coercive field E_c of the BNT thin film are 27μC/cm² and 157 kV/cm, respectively. The results of fatigue and retention tests revealed that the BNT thin film was not fatigued up to 1.44 x 10¹⁰ switching cycles and the retained charge was unchanged after 1 x 10⁵s. The leakage current behaviour of the BNT thin film was investigated at room temperature and their conduction mechanisms were also discussed. The I-V characteristics of the film show the ohmic behaviour for applied field lower than 40 kV/cm. Nonlinearity in the I-V behaviour was observed at an applied field above 40 kV/cm. In the high field region (E > 95 kV/cm) the sample shows Schottky emission.