XPS CHARACTERIZATION OF GEL-DERIVED SILICON OXYCARBIDE GLASSES

The results of an XPS study of sol-gel-derived silicon oxycarbide glas ses are presented. Si(2p) XPS peak showed the presence of all the poss ible mixed silicon oxycarbide units, i.e. SiCxO4-x, 0 less than or equ al to x less than or equal to 4. C(1s) XPS peak suggested the presence of three components at 283, 284.5-285.0 and 285.5 eV. The first two a re due respectively to carbon atoms into CSi4 sites (283 eV) and aroma tic carbon environment and/or aliphatic CHx, x=1, 2 (284.5-285.0 eV), whereas the last one has been assigned to carbon atoms sharing bonds s imultaneously with silicon and oxygen atoms forming =Si-O-C= units. It was also found that the fracture surface is richer in carbon compared with the bulk.