The electronic structure of the nanolaminated transition metal carbide ${\mathrm{Ti}}_2\mathrm{Al}\mathrm{C}$ has been investigated by bulk-sensitive soft x-ray emission spectroscopy. The measured Ti $L$, C $K$, and Al $L$ emission spectra are compared with calculated spectra using ab initio density-functional theory including dipole matrix elements. The detailed investigation of the electronic structure and chemical bonding provides increased understanding of the physical properties of this type of nanolaminates. Three different types of bond regions are identified: The relatively weak Ti $3d–\mathrm{Al}$ $3p$ bond $1\mathrm{eV}$ below the Fermi level and the Ti $3d–\mathrm{C}$ $2p$ and Ti $3d–\mathrm{C}$ $2s$ bonds which are stronger and deeper in energy are observed around 2.5 and $10\mathrm{eV}$ below the Fermi level, respectively. A strongly modified spectral shape of the $3s$ final states in comparison to pure Al is detected for the intercalated Al monolayers indirectly reflecting the Ti $3d–\mathrm{Al}$ $3p$ hybridization. The differences between the electronic and crystal structures of ${\mathrm{Ti}}_2\mathrm{Al}\mathrm{C}$, ${\mathrm{Ti}}_3\mathrm{Al}{\mathrm{C}}_2$, and TiC are discussed in relation to the number of Al layers per Ti layer in the two former systems and the corresponding change of the unusual materials properties.

• Received 22 May 2006

DOI:https://doi.org/10.1103/PhysRevB.74.195108