Metastable B-Doped Feni Compounds For Permanent Magnets Without Rare Earths

We apply first-principles calculations to metastable B-doped Fe-Ni compounds to compute their magnetic properties. We focus on crystal structures with tetragonal and orthorhombic lattices. Boron atoms, doped at interstitial sites, help in stabilizing noncubic Fe-Ni structures. At the same time, the dopants improve the magnetic properties, such as magnetocrystalline anisotropy, compared to FeNi alloys in the tetragonal L1(0)-ordered structures. The calculated magnetocrystalline anisotropy constants of 1-2 MJ/m(3) along with sufficient magnetic polarization saturation (>= 1 T) show the potential of our metastable Fe-Ni-B compounds for replacing rare-earth-based magnets in permanent-magnet applications.