混合酸制备四氟化硅气体用于硅同位素测量

<正>1引言在自然界中,硅元素有3種穩定同位素28Si,29Si和30Si,豐度分別為92.23%,3.68%和3.09%。準確測量硅的摩爾質量,需準確測量硅的3種同位素的豐度值。目前,測量硅摩爾質量最佳的方法是采用SiF4氣體測定硅同位素的豐度值,這 To determine the isotope ratios of single crystal silicon, SiF(4) gas was prepared by using the mixture acid method. After etching the single crystal silicon, the sample was dissolved with appropriate of HF and HNO(3) mixture acid. BaSiF(6) precipitation was obtained by adding BaCl(2) solution to the silicon solution, and then BaSiF(6) was decomposed into SiF(4) gas. We measure the silicon isotope ratios of SiF(4) sample by gas mass spectrometer. Some parameters were optimized in the chemical treatment. The sample was completely dissolved to yield of BaSiF(6) precipi-tation. The result shows that the SiF(4) samples are pure and the maximum errors among the SiF(4) samples are no more than 0.2 parts per thousand for delta (30)Si and for delta (29)Si, and the standard deviation is no more than 0.1 parts per thousand for delta (30)Si and for delta (29)Si.