Electronic structure investigation of MAX- phases by soft x-ray emission spectroscopy

The electronic structure of nanolaminate Ti2AlC and Ti2AlN thin films, so-called MAX-phases, were investigated by soft X-ray emission spectroscopy. These nanolaminated carbide and nitride compounds represent a class of layered materials with a combination of properties from both metals and ceramics. The bulk-sensitive soft X-ray emission technique is particularly useful for detecting detailed electronic structure information about internal monolayers and interfaces. The Ti-Al bonding is manifested by a pronounced peak in the Ti L-emission of Ti2AlC and Ti2AlN that is not present in the binary TiC system. The spectral shape of Al L-emission in the MAXphase is strongly modified in comparison to metallic Al. By replacing or partly exchanging C with N, a change of the electron population can be achieved causing a change of covalent bonding between the laminated layers, which enables control of the material properties.