An In-situ XPS study of non-evaporable ZrVFe getter material

To investigate the temperature dependence of a synthesized Zr57V36Fe7 non evaporable vacuum getter material, the in-situ temperature x-ray photoelectron spectroscopy (in-situ XPS) were performed in a UHV chamber equipped with a programmable ceramic sample heating system. The surface and bulk composition of Zr, V, and Ti was determined in the as-received state and after in-situ heating from 50℃ to 600℃ at 50℃per step. The peak fitting results for O 1s, C 1s, Zr 3d, V 2p, and Fe 2p high resolution spectra were acquired and the chemical state of the elements were then characterized as a function of heating temperature. In-situ XPS investigations showed that oxide reduction proceeds via the formation of sub-oxides with the simultaneous formation of carbides in the region near the surface. The activation temperature for completion of the Zr57V36Fe7 alloy, which approximates the XPS peaks changed from oxide to metallic state(20 % of the oxide peak), was determined around 480℃. The findings suggest that the in-situ temperature XPS technique is a useful analytical tool for evaluating activation characteristics of NEG materials.