Investigation of Changes in the Chemical Composition and Local Atomic Structure of Ti2AlC after Heat Treatment

The chemical compositions and local atomic structures of powders consisting of the MAX phase of the Ti2AlC composition, which are obtained by mechanical activation in a ball mill followed by annealing, are analyzed by X-ray photoelectron, Auger, energy dispersive X-ray, extended electron energy-loss fine structure (EXELFS) spectroscopic techniques and scanning electron microscopy. The effect of precursors on the chemical composition and local atomic structure of the Ti2AlC powder is studied. The evolution of the local atomic structure of titanium and carbon as a result of mechanical activation and heat treatment is investigated. The chemical-bond lengths and the respective coordination numbers are determined from the experimental electron energy-loss spectra. A decrease in the partial interatomic C-C and C-Ti distances is shown to be caused by annealing.