钯对钛膜吸氢能力的抗污染作用的研究

为寻求一种防止因表面污染而导致钛膜吸氢能力下降的途径，用表面分析方法检测样品表面状态，用质谱仪测量样品吸氧能力，研究了表面状态和吸氢能力的相互关系。采用在钛膜上淀积钯膜（蒸发或溅射）的方法，可使受碳、氧污染的钛膜吸氢能力得以恢复。这种钯／钛复合结构在吸氢能力上对碳、氧污染并不灵敏。对样品的近费米能级处的占有电子态密度（densityofstate，DOS）的测量证明，凡吸氢能力良好的样品，DOS呈峰形结构。具有抗污染能力的钯／钛结构，其DOS因污染而导致的变化很小，而无抗污染能力的钛膜，其峰形结构受污染作用而消失。这种峰形结构能提供氢分子解离吸附过程中所需的电子。

Contamination Resistance of the Pd Coated Ti Thin Films in Hydrogen Absorption

An attempt was made to solve the problem of contamination induced lowering of hydrogen absorption capability of Ti films. Thin Pd films coated(by deposition or sputtering)Ti film may considerably improve the hydrogen absorption capability after exposing to carbon and oxygen contaminants. To corre1ate surface properties to hydrogen absorption,surface states of the Pd/Ti composite were characterized by XPS and AES,and hydrogen absorption was studied with the mass spectroscopy. Our results showed that the electron density of occupied states(DOS)near Fermi level has a peaked structure for samples with high absorption capability of hydrogen. Little change was found of the DOS peak structure of the contami nation resist Pd/Ti samples,whereas the peak vanishes for samples without Pd because of contamination.We suggest that the effective surface dissociation sites originated from Pd atoms enhance surface absorption capability and account for the contamination resistance in hydrogen absorption.