CoFeSn, a possible contender for spintronics: A first-principles study

Anomalous carrier transport in magnetic Heusler compounds has evolved as a lively field of research owing to their unusual band structure and broken time-reversal symmetry. They have attractive properties for spintronics due to their high Curie temperature (T-c), high spin polarization, and extravagant transport properties. Here, we scrutinize CoFeSn. Based on the inferences from structural stability, lattice dynamics, and magnetic analysis, we propose a cubic polymorph of hexagonal CoFeSn and explain why we must consider cubic CoFeSn. Through density-functional-theory calculations, we predict a robust 3D half-metallic ferromagnetic compound, CoFeSn (P(4)3m) with a T-c similar to 693 K, calculated via the Heisenberg magnetic exchange interactions under mean-field approximation, and a magnetic moment of 3 lB. In addition, Wannier interpolation suggests anomalous Hall conductivity (AHC) and spin Hall conductivity (SHC) in cubic CoFeSn, the largest SHC at the Fermi level being approximate to 47 (h/2 pi e) S/cm. Our theoretical results show that spin-orbit interaction at the Fermi level brings on finite Berry flux that gives an intrinsic AHC similar to 122 S/cm at room temperature. We note that adjusting the Fermi level can be a sensible way to achieve high values of AHC or SHC. Our findings pave the way for the realization of the quantum anomalous and spin Hall effect in half-Heusler compounds.