The electronic structure of nanolaminate ${\mathrm{Ti}}_2\mathrm{Al}\mathrm{N}$ and TiN thin films has been investigated by bulk-sensitive soft x-ray emission spectroscopy. The measured Ti $L_{2,3}$, N $K$, Al $L_1$, and Al $L_{2,3}$ emission spectra are compared with calculated spectra using ab initio density-functional theory including dipole transition-matrix elements. Three different types of bond regions are identified; a relatively weak $\mathrm{Ti}3d\text{−}\mathrm{Al}3p$ bonding between $-1$ and $-2\mathrm{eV}$ below the Fermi level, and $\mathrm{Ti}3d\text{−}\mathrm{N}2p$ and $\mathrm{Ti}3d\text{−}\mathrm{N}2s$ bondings which are deeper in energy observed at $-4.8\mathrm{eV}$ and $-15\mathrm{eV}$ below the Fermi level, respectively. A strongly modified spectral shape of $3s$ states of Al $L_{2,3}$ emission from ${\mathrm{Ti}}_2\mathrm{Al}\mathrm{N}$ in comparison with pure Al metal is found, which reflects the $\mathrm{Ti}3d\text{−}\mathrm{Al}3p$ hybridization observed in the Al $L_1$ emission. The differences between the electronic and crystal structures of ${\mathrm{Ti}}_2\mathrm{Al}\mathrm{N}$ and TiN are discussed in relation to the intercalated Al layers of the former compound and the change of the materials properties in comparison with the isostructural carbides.

• Received 5 March 2007

DOI:https://doi.org/10.1103/PhysRevB.76.195127