[Quantitative surface analysis of Pt-Co, Cu-Au and Cu-Ag alloy films by XPS and AES].

In order to improve the quantitative analysis accuracy of AES, We associated XPS with AES and studied the method to reduce the error of AES quantitative analysis, selected Pt-Co, Cu-Au and Cu-Ag binary alloy thin-films as the samples, used XPS to correct AES quantitative analysis results by changing the auger sensitivity factors to make their quantitative analysis results more similar. Then we verified the accuracy of the quantitative analysis of AES when using the revised sensitivity factors by other samples with different composition ratio, and the results showed that the corrected relative sensitivity factors can reduce the error in quantitative analysis of AES to less than 10%. Peak defining is difficult in the form of the integral spectrum of AES analysis since choosing the starting point and ending point when determining the characteristic auger peak intensity area with great uncertainty, and to make analysis easier, we also processed data in the form of the differential spectrum, made quantitative analysis on the basis of peak to peak height instead of peak area, corrected the relative sensitivity factors, and verified the accuracy of quantitative analysis by the other samples with different composition ratio. The result showed that the analytical error in quantitative analysis of AES reduced to less than 9%. It showed that the accuracy of AES quantitative analysis can be highly improved by the way of associating XPS with AES to correct the auger sensitivity factors since the matrix effects are taken into account. Good consistency was presented, proving the feasibility of this method.

[Mineralogical effect correction for pressed iron ore samples in wavelength dispersive X-ray fluorescence analysis].

The possibility of correcting mineralogical effect for pressed powder pellets of iron ore samples was studied in wavelength dispersive X-ray fluorescence analysis of major and minor elements with 10 Chinese iron ore CRMs. Two methods were applied to reduce the influence of mineralogical effect. The first one is to check 20 angles for every sample before measurement to correct peak shift; another method is replacing peak intensity with peak area of the analytical line to correct the shape distortion of the spectrum. The K factors of the two methods for each element were compared to those from regular measurements. The results show that the calibration for most of the elements was improved, although to different degrees. The improvement in the calibration for sulfur is evident. The calibration for other elements can meet the general requirements except for total iron.

[Calculation of the contributions of scattering effects to the X-ray fluorescence intensities].

The contribution of scattering effects to the X-ray fluorescence intensity was studied for pure element samples, BaB binary samples and fused disk samples by theoretic calculation and experiment. Three scattering effects were considered in the present study, i. e. coherent scattering effect, incoherent scattering effect, and primary fluorescence that was scattered into the direction of detector. The study shows that the contribution of scattering effects to the intensity of fluorescence is related to the energy of the atomic absorption edge, and the sample's matrix. The higher the energy of the atomic absorption edge, the more the contribution of scattering effects to the intensity of fluorescence. The contribution of scattering effects to the fluorescence intensity is larger for light matrix samples than heavy matrix samples. The results of experiment show that the accuracy of theoretic calculation was evidently improved when the scattering effects were considered in the theoretic calculation for the intensity of fluorescence.

[Study on the influence of excitation voltage and anode on the contribution of scattering effects to the intensity of X-ray fluorescence].

The influence of X-ray tube spectral distribution related to the X-ray tube voltage and target anode on the contribution of scattering effects to the intensity of fluorescence was studied by using some fused disk samples. Three scattering effects were considered. They are coherent scattering effect, incoherent scattering effect and primary fluorescence scattered into the direction of detector respectively. For the fused beads under investigation, the results show that the contributions of coherent scattering effect and the primary fluorescence scattered into the direction of detector decreased with increasing the tube voltage, and the contribution was larger when excited by the X-ray from Cr target than that from Rh target. On the contrary, the contribution of incoherent scattering effect to the intensity of fluorescence increased with increasing the voltage, and was larger when excited by the X-ray from Rh target than that from Cr target. The sum of the contribution of scattering effects to the intensity of fluorescence increased with increasing the voltage, and was larger when excited by the X-ray from Rh target than that from Cr target.