  SmCo5 permanent magnets exhibit enormous uniaxial magnetocrystalline
anisotropy energy and have a high Curie temperature. However, a low energy
product presents a significant drawback in the performance of SmCo5 permanent
magnets. In order to increase the energy product in SmCo5, we propose
substituting fixed amount of cobalt with iron in a new magnet, SmFe3CoNi, where
inclusion of nickel metal makes this magnet thermodynamically stable. We
further discuss some basic theoretical magnetic properties of the SmCo5
compound.
