以電漿電解氧化法於鈦薄膜底材上製備鈦酸鋇膜之特性及其抗腐蝕研究

Characterization and Corrosion Resistance of Barium Titanate Films Prepared on Ti Underlayers by Plasma Electrolytic Oxidation

本研究主要是以電漿電解氧化法於Ti/Si上製備鈦酸鋇膜，並探討成膜後對抗腐蝕性質之影響。首先將Ti/Si浸置於0.5 M醋酸鋇和2 M氫氧化鈉電解液中，以定電壓模式70 V於70℃進行電漿電解氧化反應3分鐘。由X光繞射分析結果顯示，反應後之生成物為立方相鈦酸鋇。經場發射掃描式電子顯微鏡結果得知，鈦酸鋇膜表面結構為多孔結構；由橫截面圖發現鈦酸鋇膜厚約530±30 nm。於極化腐蝕分析結果發現，反應後之試片與原始Ti/Si之腐蝕電位，分別為−0.108 V和−0.262V vs. Ag/AgCl，利用電漿電解氧化法於Ti/Si上製備鈦酸鋇膜具有良好的抗腐蝕性。

Barium titanate (BaTiO3) films were synthesized on Ti/Si substrates by plasma electrolytic oxidation (PEO). Corrosion resistance of the obtained BaTiO3 films was also studied. Mixed 0.5 M Ba(CH3COO)2 and 2 M NaOH alkaline solutions were used as the electrolytes. The PEO process was conducted at a potentiostatic mode with an applied voltage of 70 V for 3 minutes at 70 ℃. Xray diffraction results showed that cubic BaTiO3 films were successfully grown. Field-emission scanning electron microscopy revealed that the BaTiO3 films possessed uniformly distributed porous morphologies. The thickness of BaTiO3 films was about 530 ± 30 nm. The corrosion potentials of the Ti/Si and BaTiO3/Ti/Si specimens were −0.262 V and −0.108 V vs. Ag/AgCl, respectively. This indicated that the corrosion resistance of the Ti/Si substrate was greatly improved by the deposition of BaTiO3 via plasma electrolytic oxidation.