Structure, magnetism, and conductivity in epitaxialTi-dopedα−Fe2O3hematite: Experiment and density functional theory calculations

We explore the feasibility of growing epitaxial $\mathrm{Ti}$-doped $\ensuremath{\alpha}\text{\ensuremath{-}}{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}$ hematite in which $\mathrm{Ti}(\mathrm{IV})$ substitutes for $\mathrm{Fe}(\mathrm{III})$ preferentially in one magnetic sublattice but not the other. Such a structure has been predicted by first-principles theory to be energetically favorable, and is expected to yield interesting and useful magnetic and electronic properties. However, we find experimentally that a majority of $\mathrm{Ti}$ dopants disperse and occupy random cation sites in both magnetic sublattices. Density functional theory predicts that the magnetically ordered and magnetically random structures are nearly isoenergetic.