APPEARANCE OF SURFACE MAGNETIC-MOMENTS ON VANADIUM THIN-FILMS AND SENSITIVITY TO CONTAMINATION

Photoelectron spectroscopy with use of synchrotron radiation shows the appearance of satellite structure in the 3s core-level spectra of freshly evaporated vanadium films on graphite. The structure is more prominent relative to the main 3s peak in islanded films, from which a greater proportion of the signal is from the surface and the features are interpreted as due to 3s electrons from multiplet split core levels in surface atoms possessing a magnetic moment. The weaker 3S component rapidly fades in an ambient pressure of 2 x 10(-11) mbar, showing that the magnetic moment is extremely sensitive to contamination. This may help to resolve the recent controversy surrounding the existence of surface magnetic moments on vanadium.