SnO2 by XPS

Tin and various tin compounds have wide utility in coatings, electronics, and catalysts, as well as having numerous biological applications. Distinguishing between different tin compounds on surfaces is an important aspect of research in many of these disciplines. In this work, x-ray photoelectron spectroscopy has been used to obtain comparison spectra of a high purity SnO2 powder. Due to rather small core level chemical shifts, it has been shown that differences in the valence band spectra provide the most direct method of distinguishing between SnO2 and SnO using XPS [see J-M. Themlin, M. Chtaib, L. Henrard, P. Lambin, J. Darville, and J-M. Gilles, Phys. Rev. B 46, 2460 (1992); P. M. A. Sherwood, ibid. 41, 10151 (1990); and C. L. Lau and G. K. Wertheim, J. Vac. Sci. Technol. 15, 622 (1978)]. The separation between the Sn 4d core level line and the most intense Sn valence band peak is also characteristic of Sn oxides [see J-M. Themlin, M. Chtaib, L. Henrard, P. Lambin, J. Darville, and J-M. Gilles, Phys. Rev. B 46, 2460 (1992) and P. M. A. Sherwood, ibid. 41, 10151 (1990)]. The valence band spectrum and the valence band–Sn 4d separation reported in this work are consistent with literature data [see J-M. Themlin, M. Chtaib, L. Henrard, P. Lambin, J. Darville, and J-M. Gilles, Phys., Rev. B 46, 2460 (1992); P. M. Sherwood, ibid. 41, 10151 (1990); and C. L. Lau and G. K. Wertheim, J. Vac. Sci. Technol. 15, 622 (1978)]. Auger parameter data may also prove useful for distinguishing between various tin compounds on surfaces. Thus, in addition to core level spectra, valence band and x-ray excited Auger spectra for SnO2 are presented. Data were obtained with a Perkin-Elmer Physical Electronics model 5600 photoelectron spectrometer using monochromatic radiation.