The TiC/TiO2 interface

The structural and chem. characterization of the TiC/rutile interface that grows in the high temp. and low oxygen partial pressure oxidn. of TiC single crystals is reported. Starting from previous kinetic data, microRaman, and AES-SEM profiles of the TiC/rutile interface cross-section, a Ti oxycarbide phase was expected to form at the TiC/rutile interface. To be consistent with the above mentioned data, Ti oxycarbide should form by partial substitution of C with O without producing any change in the rock-salt structure of TiC except small changes in the lattice parameter. The O-substitution in the C sublattice of TiC was also simulated by synthesizing Ti oxycarbide with electron gun heating of a TiC and TiO2 mixt. The final product was identified by chem. anal. and XRD as Ti1.0±0.1C0.49±0.01O0.4±0.1 having a XRD spectrum almost identical to TiC with a relative change of the lattice parameter equal to -0.8%. This result confirms the reason why no other signals other than the signals of amorphous carbon and rutile appear in the microRaman profiles, and the reliability of the oxidn. mechanism elsewhere proposed.