Structure, magnetism, and conductivity in epitaxial Ti-doped α-Fe2O3 hematite:: Experiment and density functional theory calculations

We explore the feasibility of growing epitaxial Ti-doped alpha-Fe2O3 hematite in which Ti(IV) substitutes for Fe(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 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.