First-Principles Study of Electrical Resistivity in Co $_{2}$ MnSi Compounds

Theoretical study of the electrical resistivity is performed for Heusler compounds Co₂MnSi with atomic disorder by using the first-principles techniques based on the tight-binding linear muffin-tin orbital method and Kubo-Greenwood formula. Experimentally, it is so difficult to control the degree of the ordering of the Heusler compounds precisely that their conduction property have not been clarified enough. In this study, we found that the electrical resistivities of the disordered Co₂MnSi reach about 100 μΩ cm, which is much larger than binary alloys of 3-D transition metals. By analyzing the electronic structure, we consider that the large resistivities of the disordered Co₂ MnSi are originated from the strong electrons scattering due to the low matching of electronic structure, when there is antisite type defections that break the L2₁ crystalline symmetry.