Magnetic and structural properties of Co2MnSi based Heusler compound

The influence of antisite disorder occupancies on the magnetic properties of the half-metallic Co2MnSi compound was studied by experimental techniques and first-principles calculations. The neutron diffraction studies show almost equal amount of Mn and Co disorders of 6.5% and 7.6%, which was found to be in good agreement with density functional theory (DFT) calculations of the stable Co2MnSi system with the corresponding disorders. DFT studies reveal that antiferromagnetic interactions introduced by Mn disorder lead to a reduction of the net magnetic moment. The results are discussed in conjunction with neutron diffraction and magnetization measurements. Magnetotransport measurements revealed a positive magnetoresistance for bulk Co2MnSi, which decreases as temperature increases. A Curie temperature of ∼1014 K was determined for the compound by high-temperature electrical resistivity and dilatometry measurements.