Abstract Scope |
Neutron diffraction is a powerful tool that allows to depict not only the atomic site occupancies in magnetic metal alloys, but also the magnetic site densities in each atomic position within the lattice. In this talk a combination of powder neutron diffraction, in polycrystalline samples, and non-polarized/polarized single crystal neutron diffraction measurements, in single crystals, will be discussed for a series of ferromagnetic Heusler alloys. More concretely, a series of six-element NiMnGaCoCuFe ferromagnetic shape memory alloys is studied using the aforementioned techniques. Based on the atomic site occupancies and additional measurements of the saturation magnetization, the influence of the structure and atomic ordering on the magnetism in these materials is analysed. The most promising candidate to present magnetic actuation at high temperatures was grown as single crystal and studied by single crystal neutron diffraction, obtaining a full map of the spin densities in the unit cell of the crystal. |