Antiferromagnetic I-Mn-V semiconductors

After decades of research, the low Curie temperature of ferromagneticsemiconductors remains the key problem in the development of magnetic-semiconductor spintronic technologies. Removing this roadblock might requirea change of the eld’s basic materials paradigm by looking beyond ferromagnets.Recent studies of relativistic magnetic and magneto-transport anisotropy e ects,which in principle are equally well present in materials with ferromagneticallyand antiferromagnetically ordered spins, have inspired our search for antiferro-magnetic semiconductors suitable for high-temperature spintronics. Since theseare not found among the magnetic counterparts of common III-V or II-VI semi-conductors, we turn the attention in this paper to high Neel temperature I-II-Vmagnetic compounds whose electronic structure has not been previously iden-ti ed. Our combined experimental and theoretical work on LiMnAs providesbasic prerequisite for the systematic research of this class of materials by demon-strating the feasibility to grow single crystals of group-I alkali metal compoundsby molecular beam epitaxy, by demonstrating the semiconducting band struc-ture of the I-Mn-V’s, and by analyzing their spin-orbit coupling characteristicsfavorable for spintronics.All current spintronic applications are based on ferromagnetically (FM) ordered spinsof transition metals such as Ni, Co, Fe and their alloys.