Effect of annealing temperature on ferroelectric properties of (Bi, Nd)4(Ti, V)3O12 thin films
(1.Faculty of Materials and Optoelectric Physics, Xiangtan University, Xiangtan 411105, China;Key Laboratory of Low Dimensional Materials and Application Technology, Ministry of Education, Xiangtan University, Xiangtan 411105, China2.Faculty of Materials, Optoelectronics & Physics, Xiangtan University, Xiangtan 411105, China)
Abstract: Thin films of Nd3+/V5+-cosubstituted bismuth titanate, (Bi3.5Nd0.5)( Ti2.96V0.04)O12 (BNTV), were fabricated on the Pt(111)/Ti/SiO2/Si(100) substrates by a chemical solution deposition technique and annealed at different temperatures of 650, 700, 750 and 800 ℃. The surface morphology and ferroelectric properties of the samples were studied in detail. The result shows that the film annealed at 800 ℃ indicates excellent ferroelectricity with a remanent polarization of 2Pr=40.9 μC/cm2, a coercive field (EC) of 114 kV/cm at an applied electrical field of 375 kV/cm. The substitution of Ti-site ion by V5+ ions could improve the upper limit of the optimal annealing temperature by decreasing the space charge density in BNT thin film. Additionally, the mechanism concerning the dependence of ferroelectric properties of BNTV thin films on the annealing temperature was discussed.
Key words: ferroelectric properties; annealing; scanning electron microscopy; crystallization