A first-principles study of stabilities, magnetic, electronic, elastic and transport properties of the metal borides TM2B (TM = Mn, Fe, Co and Ni)

This work addresses the physical properties of the highly correlated electron systems; transition metal borides TM2B (TM = Mn, Fe, Co and Ni) and provides a solid foundation for resolving the longstanding debate concerning the stable magnetic phase of Mn2B. The generalized gradient approximation along with Hubbard U (GGA + U) approach handling the high correlated electron systems; a valuable insight into this article has been utilized in the domain of Density Functional Theory. The calculated lattice parameters are found consistent with the experiments. The optimization energies in different magnetic phases and magnetic susceptibilities reveal that Mn2B is antiferromagnetic (AFM) in nature. The replacement of the TM in these intermetallics; transform the AFM behavior of Mn2B in to ferromagnetic (Fe2B and Co2B) and then paramagnetic (Ni2B), respectively. Electronic properties, electrical resistivities and thermal electronic conductivities of these compounds confirm their metallic nature. The investigated elastic properties demonstrate the stability and show that Fe2B is harder and brittle among this series while the rest compounds are ductile. All these intermetallics are incompressible and possess high melting temperatures. Based on the above properties, it is expected that these compounds could be used in high temperature technology like furnaces, reactors, aerospace and other high temperature processing equipments.