Abstract
Electron probe micro analyzer is used for the composition analysis of a wide variety of materials, and its quantification is almost established as a ZAF method. The quantification of MgGe alloy, however, showed an anomalously-high total concentration (i.e. 120%) of the elements of Mg and Ge. The previous analysis of MgGe alloy was not considered to be correct according to the additional fact that the estimated concentrations of Mg increases with the accelerating voltage of the electron beam. Because the mass absorption coefficient of Ge for Mg Kα , is an essential parameter of the ZAF method, we then determined the mass absorption coefficient of Ge for Mg Kα by using measured X-ray peak intensity ratios of Ge and Mg of MgGe alloy to the standard materials (MgO and Ge). The resulting mass absorption coefficient of Ge for Mg Kα was 5561± 200 cm2⁄g which were obtained between the electron-beam accelerating voltage of 15kV ∼ 30kV. It is smaller than the previous mass absorption coefficient of 7510 cm2⁄g, which lead the anomalous quantification error. The difference of the mass absorption coefficients must be caused by the difficulty of the measurement of the mass absorption coefficient of Ge for Mg Kα, the energy of which are close to the Ge LI and LIIabsorption edges.
