退火处理对钛酸钡微弧氧化铁电薄膜物相的影响

Effect of annealing treatment on phase composition of barium titanate ferroelectric thin film prepared by microarc oxidation

以工业纯钛板作为阳极,在Ba(OH)2溶液中微弧氧化制得BaTiO3薄膜。研究了BaTiO3薄膜的表面形貌和物相组成,着重研究了退火处理对BaTiO3薄膜物相的影响。微弧氧化所得薄膜表面凹凸不平,且存在大量分布不均的孔洞,主要由六方相BaTiO3组成,经不同温度退火后,其物相组成发生很大变化。在1 100°C下退火1 h后,薄膜中开始出现四方相BaTiO3;随着热处理温度的升高和保温时间的延长,更多的BaTiO3由六方相向四方相转变。但高温退火过程中基体Ti与微弧氧化膜反应形成的氧化物层会影响薄膜的铁电性能。

A BaTiO3 thin film was prepared from Ba（OH）2 solution using titanium plate as anode by microarc oxidation. The surface morphology and phase composition of BaTiO3 thin film were studied. The effect of annealing on phase composition of BaTiO3 thin film was discussed. The surface of as-prepared thin film is uneven and there are many irregularly distributed holes. The as-prepared thin film is mainly composed of hexagonal BaTiO3. The phase composition of BaTiO3 thin film changes a lot after annealing at different temperatures. Tetragonal BaTiO3 film is formed after annealing at 1 100 ℃ for 1 h. With the increase of annealing temperature and the prolonging of time, more BaTiO3 transfer from hexagonal phase to tetragonal one. However, the oxide layer which is formed by the reaction between Ti substrate and microarc oxidation film during high temperature annealing process is likely to influence the ferroelectric properties of thin film.