【摘要】 用电容测量技术和电化学阻抗技术研究了高纯钽丝在稀磷酸(质量分数为0.01%,0.10%和1.00%)、氨水(pH=11)和饱和CO2水溶液(pH=4)中阳极氧化形成的氧化钽膜在酸性缓冲液(pH=2)中的半导体性和阻抗特性。实验结果表明,来自非磷酸系的阳极氧化钽膜呈现出双极性(p-n)半导体结构特征,而来自磷酸系的则表现为三极性(n-p-n);且非磷酸系阳极氧化钽膜的施主浓度(0.6×1019cm–3)明显低于磷酸系的(0.7×1019~2.2×1019cm–3)。但磷酸系阳极氧化钽膜的耐酸腐蚀性弱于非磷酸系的。这些可能是磷酸根离子嵌入氧化钽膜外层的结果。更多还原

【Abstract】 Capacitance measurement and electrochemical impedance spectroscopy(EIS) were used to investigate the semiconducting properties and corrosion resistance of tantalum oxide films formed by anodic oxidization of Ta wires immersed in diluted phosphoric acids(mass fraction 0.01%,0.10% and 1.00 %),ammonia(pH=11) and saturated carbonic acid(pH=4) respectively.The results show that the anodic tantalum oxide films formed in ammonia and saturated carbonic acid possess the dipolar(p-n) semiconducting characteristics,and the films formed in diluted phosphoric acid present the tripolar(n-p-n) semiconducting characteristics.Moreover,the donor concentrations of the films from ammonia and saturated carbonic acid are about 0.6×1019cm–3,being lower than that from the dilute phosphoric acids(0.7×1019~2.2×1019cm–3).The corrosion resistances of the films from ammonia and carbonic acid were evidently higher than that from the dilute phosphoric acid.The results are the consequence of the incorporation of phosphate ion in the outer portion of the anodic tantalum oxide films.更多还原