元素在石墨炉内石墨探针表面上的原子化机理研究——Ⅶ.锗的原子化机理

Atomization Mechanism of the Elements on the Graphite Probe Surface in the Graphite Furnace Ⅶ. The Atomization Mechanism of Germanous Fluoride and Sodium Germanate

本文应用X-射线衍射、X-射线光电子能谱、俄歇电子能谱和其它一些实验,考察石墨炉升温过程中氟化锗、锗酸钠在石墨探针表面上的形态变化,阐明了它们的原子化机理:GeF_2与Na_2GeO_3首先分解为GeO_2,GeO_2还原为GeO,后者在>2400K热分解产生自由态的锗原子,GeF_2和Na_2GeO_3的原子化均源于GeO(g)的气相分解。在原子化的升温过程中,在1400～2400K GeF_2和Na_2GeO_3都产生了挥发性锗化合物的损失,这种挥发损失是GeO(g)造成的。

The atomization mechanism of germanous fluoride and sodium germanate from the graphite probe surface in the graphite furnace has been studied by X-ray diffraction spectrometry, X-ray photoelectron spectrometry, Auger electron spectrometry and graphite furnace atomic absorption spectrophotometry. The mechanism of the formation of germanium atoms for GeF2 and NazGeO3 was proposed,respectively. GeF2 and Na2GeO3 were changed first into GeO2 and then GeO,followed by thermal dissociation of GeO to form free atoms of germanium at temperature T≥2400 K. The atomization of germanous fluoride and sodium germanate on the graphite probe surface originates from the thermolysis of GeO(g) in gas phase. Both GeOF2 and NazGeO3 produce the volatilizable GeO(g) in temperature of 1400-2400 K in the course of increasing temerature during atomization. The loss of germanium results from GeO(g).