Electronic structure and magnetic properties of doped Al$_{1-x}$Ti$_{x}$N ($x$ = 0.03, 0.25) compositions based on cubic aluminum nitride from ab initio simulation data

The phase stability, electronic structure, and magnetic properties of Al$_{1-x}$Ti$_{x}$N compositions based on the metastable aluminum nitride modification with the rock-salt structure at low ($x$ = 0.03) and high ($x$ = 0.25) concentrations of titanium in the system have been investigated using the results of ab initio band calculations. It has been shown that, at low values of x, the partial substitution is characterized by a positive enthalpy, which, however, changes sign with an increase in the titanium concentration. According to the results of the band structure calculations, the doped compositions have electronic conductivity. For $x$ = 0.03, titanium impurity atoms have local magnetic moments ($\sim$0.6 $\mu_{\mathrm{B}}$), and the electronic spectrum is characterized by a 100% spin polarization of near-Fermi states. Some of the specific features of the chemical bonding in Al$_{1-x}$Ti$_{x}$N cubic phases have been considered.