Effect of Doping on the Electronic Structure of the Earth's Lower Mantle Compounds: FeXO₃ with X = C, Al, Si

The effect of the mutual doping of C, Si, and Al atoms on the electronic structure and magnetic properties of FeXO₃ (X = C, Al, Si) compounds, which are constituent compounds of the Earth's lower mantle, was studied. In our first principles calculations, it was found that doping with carbon for both FeSiO₃ and FeAlO₃ leads to the transition of the compound from a half-metallic state to a metallic one. The values of the magnetic moments of Fe were obtained for pure and doped compounds. For the doped compounds, there is a tendency of the Fe magnetic moment to increase with the growth in the number of substituted ions in the case of replacing Si with C and Si for Al; on the contrary, in the case of replacing Al with C and Si, a decrease in the magnetic moment was revealed. For FeXO₃ (X = C, Al, Si), the obtained magnetic moment values were found to be in a good agreement with the known experimental data.