非导电材料元素X-射线显微分析的补偿和校正方法

Compensation and Correction of Elemental X-Ray Analysis of Non-Conducting Materials

本文分析了在环境扫描电镜中,Al2O3等非导电陶瓷样品的荷电效应和环境压力对X-射线能谱仪(EDS)元素分析造成的影响。研究了相应的补偿和校正方法。在高真空模式下,荷电效应使氧含量明显增加。采用低真空模式(LV)消除了荷电效应和减小了表面电势,因而减小了EDS的测量误差。在LV模式中采用X-射线压力限制光阑(PLA)杯,减小了电子束的裙散效应,使EDS的测量误差进一步减小。较高的压力环境增加了对电子束和低能X-射线的散射作用,使EDS的测量误差明显增加。

The influence of the charged surfaces of non-conducting materials （ such as ceramic Al2O3） and the atmospheric pressure on X-ray energy dispersive spectroscopy （EDS） analysis with environmental scanning electron microscopy （ESEM） was experimentally studied. And the appropriate compensation and corrections were proposed. We found that in high vacuum, the charge effect increases the oxygen contents in EDS spectrum, and that the EDS errors can be reduced by lowering the pressure because low vacuum eliminates the charge effect and decreases the surface potential. The X-ray pressure limit aperture （PLA） can further reduce the errors by weakening the beam skirt scattering. The scattering of both the electron and the low energy X-ray by higher pressure, accounts for the large EDS errors.