화학공학소재연구정보센터
Journal of Vacuum Science & Technology A, Vol.17, No.5, 2668-2675, 1999
Cryogenic stabilization of high vapor pressure samples for surface analysis under ultrahigh vacuum conditions
A novel form of ultrahigh vacuum (UHV) cryogenic stabilization has been used to obtain high-resolution x-ray photoelectron -spectroscopy (XPS) data from a complex amine, 1,8-bis(dimethylamino) naphthalene, whose solid phase exhibited at room temperature an unacceptably high rate of sublimation. Protonated versions of the amine exhibit hydrogen bonding. Electron spectroscopy for chemical analysis chemical shifts can be used to describe the strength and asymmetry of hydrogen bonding formed in proton sponge complexes. Analyzing the binding energy shifts of N (1s) induced by the presence of this hydrogen bonding required obtaining corresponding XPS spectra from the nonprotonated (reference) sample, but the reference sample sublimes under even moderate vacuum conditions. The combined results suggest that other high vapor pressure materials, particularly those that were previously considered to be too corrosive for routine analysis, can be cryogenically stabilized for surface analysis under similar UHV conditions.