Fe离子注入ZrO_2的研究(英文)

Investigations of Ion Implanted in Zirconia

陶瓷材料的表面性能在很大程度上取决于其表面条件.例如:陶瓷的表面微裂纹影响着机械强度,而磁学及电学性能则对其表面结构及化学成份非常敏感.近年来离子注入法已经开辟了研制现代材料的新途径,并被广泛应用于金属、半导体及部分聚合物材料中.对于陶瓷材料,目前大多数有关这方面的研究集中于改善陶瓷表面的机械性能,很少有论文涉及其表面电性能的改善.本文介绍了一种改善ZrO2陶瓷表面导电性能的新方法.ZrO2陶瓷是绝缘体,常温下其电阻率大于1012Ωcm.通过不同剂量的离子注入可以使得样品表层产生不同程度的电性能变化.试验表明,当采用2×1017Fe/cm2注入,并在950℃下真空退火30分钟,ZrO2的表面电阻率将下降十余个数量级,从而大幅度提高了样品的导电性.文中还通过应 用X射线衍射及光电子能谱技术,分别对注入元素的化学结合状态及表面注入层的结晶相进行了较为详细的讨论.从XPS测试发现,注入离子在ZrO2表层中以Fe2+、Fe3+及Fe0三种形式的状态存在;X射线衍射数据表明,注入层中除ZrO2主晶相外,还存在少量的FeZrO3等晶相.文章的最后部分讨论了离子注入样品的导电机制.

This paper describes a new method to improve the surface conductivity of ZrO2 ceramics. The experimental results show that ion implantation is an important technology. Various doses of the implanted ions cause various electrical property changes. At high doses, the surface resistivity of ZrO2 is reduced by more than ten orders of magnitude, so the electrical properties of specimens are improved considerably. The chemical bonding states of the implanted elements and the crystalline phase in the surface layer are discussed respectively by means of X-ray Photoelectron Spectroscopy (XPS) and X-ray Diffraction (XRD). XPS measurements show that the implanted ions exist in the surface film of ZrO2 in three kinds of chemical bonding states, i.e. Fe2+ , Fe3+ and Fe0(metallic). X-ray Diffraction shows that besides the main phase ZrO2, there is a small amount of the new phase of FeZrO2 formed in the implanted layer. The conductivity mechanism of the implanted specimen has been discussed finally depending on the energy deposition theory.