微弧氧化工艺参数对BaTiO3和SrTiO3薄膜生长的影响

将工业纯Ti板(99.5%)分别置于Ba(OH)2、Sr(OH)2+NaOH溶液中微弧氧化制备BaTiO3和SrTiO3陶瓷薄膜。XRD分析表明:所制备的薄膜分别主要由四方相BaTiO3和立方相SrTiO3组成。测得最优工艺条件下所得两种薄膜在100 Hz下的介电常数分别为152.3和419.1,介质损耗(tanδ)值分别为0.096和0.045。重点研究了微弧氧化工艺参数对薄膜生长的影响规律,结果表明:随着电解液溶度、电流密度的增加以及电流频率的降低,薄膜的生长速度加快;提出并验证了薄膜生长动力学的经验公式。

Effects of technological parameters on growth of BaTiO_3 and SrTiO_3 film prepared by microarc oxidation

Microarc oxidation(MAO) of titanium was conducted in aqueous electrolyte containing barium hydroxide,or both strontium hydroxide and sodium hydroxide.As shown by X-ray diffraction(XRD),the main phase of the films deposited in these two kinds of electrolyte was tetragonal barium titanate and cubic strontium titanate,respectively.Under the optimized processing conditions,the dielectric constant was 152.3 and 419.1 for BaTiO3 and SrTiO3,respectively,with the dielectric loss(tanδ) being 0.096 and 0.045.The influences of processing parameters on growth of the MAO film were discussed.It is demonstrated that with the increase of the concentrations,current densities and the decrease of the current frequencies,the deposition rate is increased.A kinetic growth equation is established for the MAO film thickness and is found to agree well with the experimental results.