Magnetism and Half-Metallicity of Solids from the Spin Polarization of P Orbitals

Heusler alloys are of great scientific and technological interest. In addition, devices based on Heusler alloys exhibit a development of new structures with ferromagnetic behavior using transition metals or elements that are inherently non-magnetic. Half-Heusler type XYZ and full- Heusler type X₂YZ alloys without transition metals, mainly called d⁰ ferromagnetic half-metals (FHM) is a recent research field. The particular interest of their ferromagnetic character as well as of the half-metallic (HM) nature with possible applications in spintronic systems does not come from magnetic elements. This series of strongly ferromagnetic materials mentioned above is composed of non-magnetic elements compared to those predicted by Groot et al. in 1983. Recently, some studies have also demonstrated the presence of half-metallicity in compounds without partially filled d atomic orbitals such as alkaline earth carbides and nitrides.