A COMPARATIVE-STUDY OF OXIDATION OF TI AND COTI BY HREELS AND XPS

High resolution electron energy loss spectroscopy (HREELS) has been used in conjunction with X-ray photoelectron spectroscopy (XPS) to study the oxidation of Ti(0001) and CoTi at room temperature. Oxygen exposure of Ti(0001) produces a HREELS loss peak at 65meV for exposures up to 0.5L. Thereafter a shoulder appears at 87meV and becomes the dominant loss peak after 25L exposure. The high energy peak continues to grow in intensity for exposures up to 17,000L and shifts upward in energy to 95meV. Similar changes in HREEL spectra accompany oxidation of CoTi, although the intensity of loss peaks grows more slowly than for Ti. The HREELS results are in broad agreement with XPS data, pointing to TiO2 as the limiting oxide phase on both Ti and CoTi.