Structural and magnetic properties of SmCo5−XNiX intermetallic compounds

Abstract

Modern technological applications in an extensive variety of fields require the use of Permanent Magnets (PMs). Intermetallic compounds such as SmCo5 are already used as high-performance PMs. Reducing the high content of the expensive cobalt in SmCo5 from low-priced transition metals can lead in a cost reduction. This study examines by computational methods the effect of substituting cobalt atoms in the crystal structure of SmCo5 by nickel atoms. The aim is to specify the structure that will be stable and at the same time will maintain high values of magnetization. A series of atomistic simulations are implemented based on Density Functional Theory calculations. Various simulations are performed by considering all possible crystallographic positions of Co and Ni atoms in a SmCo5−xNix compound. Based on energy minimization and maximizing the magnetization we pinpointed the interesting cases. An experimental implementation based on the sample with x = 1 is presented to translate the findings from atomistic simulations to realizable bulk materials. Interestingly, it is concluded that in many cases an energetically favourable atomistic configuration does not exhibit maximum magnetization. It should be noted that for the experimentally investigated case of SmCo4Ni, both the energetically favourable as well as the magnetically maximum configuration have been identified.