Cu-Al-Mg合金表面氧化膜分析

Structural analysis of Cu Al Mg alloy surface oxide film

利用俄歇能谱、X射线电子能谱和扫描电镜对Cu Al Mg合金表面氧化膜进行了分析。结果表明 :氧化膜由MgO和Al2 O3 组成 ;没有进行过氧化处理的样品膜内的Al和O含量高于进行过氧化处理的样品 ,而Mg则相反 ;Al2 O3 的键合能E2 p3 / 2 值大于MgO的E2 p3 / 2 值 ,表明Al2 O3 不易被分解 ;进行电子轰击后 ,膜内Mg含量减少 ,MgO被部分分解 ,而Al则增加。由MgO和Al2 O3 组成的复合型氧化膜使得合金既具有高的二次电子发射系数又有长的寿命 ,因此 ,Cu Al Mg合金是一种理想的二次电子发射材料。

In order to clarify the mechanism of the secondary electron emission, the Cu Al Mg alloy surface was analyzed by Auger emission spectroscopy (AES), X ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). AES analysis proved that the oxide film of mixed MgO and Al 2O 3 are deposited on the alloy surface. XPS proved that the bonding energy ( E 2p3/2 ) of Al is larger than that of Mg, which indicates that the bond strength of Al 2O 3 is stronger than that of MgO. SEM observation of the component change of oxide film after electron bombardment showed that MgO is partially decomposed. Therefore the mixed MgO and Al 2O 3 oxide film, deposited on the surface of Cu Al Mg alloy, is better than single oxide film in its structure, which presents better emission property for secondary electron. Al is considered as the critical factor for increasing Cu Al Mg alloy emission life. [