CORE-LEVEL STUDY OF WSI2(110)

Angle resolved core level studies of the Si 2p and W 4f levels have be en carried out on the (110)surface of a WSi2 single crystal using sync hrotron radiation. Surface shifted components have been revealed both in the Si 2p and W 4f spectra. Investigations were carried out at two different annealing temperatures. The results indicate Si enrichment a t the surface, and a larger enrichment after the higher temperature an neals. The reactivity upon initial oxygen exposure was investigated. S trong Si oxidation was observed but chemically shifted W 4f components could also be detected.