关键词: magnetic anisotropy, biaxial strain, electronic band structure, mechanical properties

Abstract: The electronic structure, elasticity, and magnetic properties of the Mn$_{2}X$In ($X={\rm Fe}$, Co) full-Heusler compounds are comprehensively investigated via first-principles calculations. The calculated elastic constants indicate that both Mn$_{2}$FeIn and Mn$_{2}$CoIn possess ductility. At the optimal lattice constants, the magnetic moments are found to be 1.40 $\mu_{\rm B}$/f.u. for Mn$_{2}$FeIn and 1.69 $\mu_{\rm B}$/f.u. for Mn$_{2}$CoIn. Under the biaxial strain ranging from $-2$% to 5%, Mn$_{2}$FeIn demonstrates a remarkable variation in the spin polarization, spanning from $-2$% to 74%, positioning it as a promising candidate for applications in spintronic devices. Analysis of the electronic structure reveals that the change in spin polarization under strain is due to the shift of the spin-down states at the Fermi surface. Additionally, under biaxial strain, the magnetic anisotropy of Mn$_{2}$FeIn undergoes a transition of easy-axis direction. Utilizing second-order perturbation theory and electronic structure analysis, the variation in magnetic anisotropy with strain can be attributed to changes of d-orbital states near the Fermi surface.

Key words: magnetic anisotropy, biaxial strain, electronic band structure, mechanical properties