DENSITY OF VALENCE STATES IN AMORPHOUS C AND SiC.

The densities of valence states (DOVS) of sputtered films of a-C and a-SiC have been determined by X-ray and u. v. photoelectron spectroscopy. The DOVS of a-C agrees well with a broadened version of one calculated for diamond, even though the structure of a-C is known to contain both graphite and diamond bonds. The effect of second neighbour interaction on the DOVS is estimated through a simple model band calculation. The broadening (0. 5-0. 7 eV) of the core levels and features of the DOVS in a-SiC indicates chemical disorder, in agreement with the interpretation of X-ray diffraction results.