Comparative study of oxidation of Co3Ti, CoTi and CoTi2 by X-ray photoelectron spectroscopy
Abstract
The interaction of Co3Ti, CoTi and CoTi2 with O2 at room temperature has been studied by X-ray pnotoelectron spectroscopy (XPS). For all three materials, oxygen exposure in the regime up to 15000 L (1 L = 133.322 Pa s) leads to formation of a Ti oxide overlayer without oxidation of the Co component of the alloy. The rate of oxidation correlates with the density of states at the Fermi energy and follows the sequence Co3Ti > CoTi > CoTi2.