Fe magnetic moment formation and exchange interaction in Fe2P: A first-principles study

Electronic structure and magnetic properties of Fe2P have been studied by a first-principles density functional theory calculation. The ground state is ferromagnetic and the calculated magnetic moments for Fe1 (3f) and Fe2 (3g  ) are 0.83 and 2.30μB, respectively. The nearest neighbor inter-site magnetic exchange coupling parameter at the Fe1 layer (0.02 mRy) is much smaller than that at the Fe2 layer (1.29 mRy). The Fe moment at the 3f   site is metastable and sensitive to the inter-site exchange interaction with its magnetic neighbors, which is responsible for the first order magnetic transition and large magneto-caloric effect around TCTC.

► Fe magnetic moment formation in Fe2P was studied from first-principles.
► Exchange interaction varies substantially for the different Fe–Fe pairs.
► Fe moment of 3f site is metastable, related to the first order magnetic transition.