Local chemical bonding and structural properties in Ti 3 Al C 2 MAX phase and Ti 3 C 2 T x MXene probed by Ti 1 s x-ray absorption spectroscopy

The authors investigate the MAX phase material Ti${}_{3}$AlC${}_{2}$ and the corresponding MXene material Ti${}_{3}$C${}_{2}$T${}_{x}$, where the latter was examined before and after a series of heat treatments. The Ti-C bond lengths in the Ti${}_{3}$C${}_{2}$-layers are altered when the stronger interacting F and O in Ti${}_{3}$C${}_{2}$T${}_{x}$ replace the Al-monolayer in Ti${}_{3}$AlC${}_{2}$ and an additional heat treatment to 750 \ifmmode^\circ\else\textdegree\fi{}C changes the Ti-O/F coordination.