Investigation of structural and magnetic properties of Fe-Rh-(Z) (Z = Co, Pt) alloys by first principles method

In this work, we present theoretical investigations of the structural and magnetic properties Fe (Rh, Co) and Fe (Rh, Pt) alloys using the density functional theory. The energy calculations were performed for the 16-atom supercell (Fe8Rh8-xZx) with different initial spin configurations. It is shown that a small variation of Pt or Co content leads to change the type of magnetic ordering. It is shown that the ferromagnetic configuration of Fe8Rh8-xCox (x=2, 3) is more energetically favorable as compared with other configurations in austenite. The antiferromagnetic configuration is more energetically favorable for Fe8Rh7Co1 alloy. For the Fe8Rh8-xPtx system, the checkerboard-like antiferromagnetic configuration was found to be more energetically favorable. Besides, the addition of Pt into Fe-Rh system slightly changes the optimized lattice parameter and stimulates the martensitic phase transformation