高性能陶瓷材料的俄歇能谱分析

降低陶瓷材料表面电荷的积累一直是俄歇分析技术能否成功应用于该类材料必须解决的首要问题. 通过实验认为：陶瓷材料试样减薄法可以用来降低表面电荷.采用这种方法，样品可分析区域大小仅依赖于电子束斑尺寸. 因而，用Microlab 310--F热场发射扫描俄歇微探针分析仪能在几十纳米的微区内，获取结构信息和除氢氦外的化学成分信息，突破了陶瓷材料在低电压、低电流下约几十微米的分析范围. 在此基础上，挑选了掺Dy的α-Sialon ，掺Y、La的α-Si₃N₄与以Al₂O₃为基体加入SiC晶须, 并通氮气氛处理的三种高性能陶瓷作为实验对象，分析和研究它们的晶粒、界面的成份、化学态和结构.发现α-Si₃N₄和α-Sialon陶瓷中的Si(LVV, KLL)峰位都会向低能端漂移,峰位分别为: 84eV 和1613eV. Si--N--O的结合态又使Si(LVV)峰继续漂移到80eV左右. 掺Y、La的α-Si₃N₄的玻璃相区, Si至少以两种或者两种以上的化学态存在.掺Dy的α-Sialon陶瓷的局部区域内有四种组分不同的固溶相及三种组分不同的晶间相. 另外, 在SiC与SiC-BN-C纤维补强复合陶瓷材料的断裂面，观察到从SiC基体拔出的纤维表面的大部分是残留的C层与C-BN交界层.

AES and SAM Analysis of High Performance Ceramics

Effective reducing the charging on surface of ceramics is the key point of AES and SAM analysis in ceramic materials. After the preparation of them by thinning, the charging sharply drops down on the surface of ceramic samples, thus opening up a new application of AES and SAM technology in the analysis of a few tons of nm size microarea since the electron beam with a high beam energy and a small spot can be focused on the samples without obvious charging. Therefore, with a Microlab 310-F Thermal Field Emission Scanning Auger Microprobe, the chemical composition (except for H and He elements), chemical state and structure can be identified at about 30nm areas. In this paper, four kinds of high performance ceramic samples were discussed, ① doped Dy α-Sialon, ② doped Y, La α-Si₃N₄, ③ Al₂O₃+SiC whisker composite through nitrogen and ④ SiC matrix + C-on-BN-on-SiC multilayer fiber composite. It was observed that Si(LVV) and Si(KLL) shift to 84eV and 1613eV respectively in kinetic energy and the former keeps on shifting to about 80eV due to the binding of Si-N-O. Four different solid solution phases and three different intergranular phases exist in some microareas of ① sample and Si shows two or more than two kinds of binding states in the intergranular phases of ② sample. In addition, C layer and the C-BN interlayer can be detected on the surface of C-on-BN-on-SiC multilayer fibers pulled out from the fractured SiC matrix.