Materials design of transparent and half-metallic ferromagnets of MgO, SrO and BaO without magnetic elements

We propose materials design to fabricate a new class of diluted magnetic semiconductors (DMSs) based on MgO, SrO and BaO without magnetic elements. Replacing the oxygen atoms by other atoms such as C atoms leads to the induction of a deep-impurity band. These materials show ferromagnetic behaviour if the impurity-band width (W) and the electron-correlation energy (U) satisfy the conditions of a highly correlated electron system (U > W). Based on first-principles calculations, we demonstrate that these materials could satisfy Stoner's condition, and could be new candidates for transparent and half-metallic ferromagnetic DMSs without any magnetic elements.