A Study On X-ray Fluorescence Spectrometry Analysis For Major And Minor Components In Barium Titanate

In the electronic field, barium titanate is widely used due to its special performance. And because of its low cost, simple synthesis method, easy doping modification, barium titanate is a fine chemical product which has a broad development prospect with its high added value. With the development of the electronic industry, the demand of sense organ is continuously on the increase. Meanwhile, quality management system is established, as a result, the quality requirement of the raw material of electronic components is much higher, the impurity content index of barium titanate is developing in the direction of trace or even super trace, therefore, great attention is paid on the establishment of a corresponding simple, reliable analysis method.According to the latest chemical industrial standard, the determination of chemical index of barium titanate of electronic level involves chemical methods, inductively coupled plasma atomic emission spectrometry and optical spectrophotometry techniques, among which the popularizing rate of inductively coupled plasma atomic emission spectrometer is relatively low in domestic material and component industry due to its high cost, and all these methods have a long analytical cycle with the complicated sample pretreatment of decomposition; Matrix effect is relatively serious, the detection sensitivity and accuracy of Al,Si,Fe,Sr remain to be further enhanced. In this thesis, the impurity elements of Ba,Ti,Fe,Sr were analysed by energy dispersive X-ray fluorescence spectrometry, and the sample powder was directly pressed into discs and used in the analysis. On the premise of accuracy, the complicated chemical pretreatment and analysis process were avoided, the analysis cycle was shortened. For light elements Al and Si whose detection sensitivity couldn't be satisfied by energy dispersive X-ray fluorescence spectrometry, this paper adopted the extraction spectrophotometry to realize the continuous determination of them, with sensitivity to be higher, matrix interference to be smaller,and the results to be correct and reliable.This thesis mainly solved the following problems:1) The detection sensitivity of Fe and Sr using energy dispersive X-ray fluorescence spectrum is not very high. This paper studied the analysis condition, such as tube excitation voltage and the use of different filters, and sensitivity was greatly improved . 2) The determination of chemical components by energy scattering-X-ray fluorescence spectrometry relies on standard samples, while barium titanate standard samples are not available in our country at present. Based on the content range of major and minor chemical components in s barium titanate, the calibration sample series were prepared by adding a range of different volumes of standard solution of impurity elements to high purity barium titanate, which was a solution to the lack of standard samples.3) In the analysis of element with relatively low atomic number such as Ti, the matrix effect of barium titanate cannot be ignored. In this paper, matrix effect was respectively corrected by the dj mode and Compton scattering line internal standard method, and after the comparison and the analysis of two methods, a conclusion was drawed that dj method was superior to Compton scattering line internal standard method. Apply the dj method to the actual analysis of barium titanate samples, the relative standard deviation of the testing results of Ba,Ti was less than 0.14%, while the respective detection limit of impurity element Fe,Sr was 0.0013%, 0.0011%.4) The accuracy and precision of the analysis results of Si,Al according to the determination method of industry standard is expected to be improved. In this paper, extraction - spectrophotometry was used in the continuous determination of Si and Al. The sensitivity of Silicon-molybdenum blue pectrophotometry was not very high, through extraction by butanol, the sensitivity of silicon was more than doubled, molar absorption coefficient was increase from 8.0×10~3 L/(mol·cm) to 1.8×10~4 L/(mol·cm). For the analysis of aluminum, the sensitivity was greatly improved after extraction, molar absorption coefficient was increased from 1.4×10~4 L/(mol·cm) to 6.13×10~4 L/(mol·cm), besides, during the process, aluminum was effectively separated from the matrix Ti which was an interference element to the analysis of aluminum. Thus the determination of all indications of barium titanate was simplified, involving the least instruments, and experimental results were correct and reliable. The recovery test of Si was 94.3~108.0%, and the recovery test of Al was 95.0~106.3%.