Theoretical Investigation of Magnetic Structure and Hyperfine Field of NaCl-Type FeN

The electronic and magnetic properties of NaCl-type FeN and the hyperfine field at Fe sites in NaCl-type FeN are investigated by band calculations using a full-potential linearized augmented-plane-wave method. The equilibrium lattice constant obtained theoretically (∼4.0 Å) is much smaller than the experimental value (4.50 Å). For our estimated equilibrium lattice constant the ferromagnetic state is more stable than the non-magnetic state and two kinds of antiferromagnetic state (q = (π, π, π), q = (0, 0, π)). The hyperfine field of the ferromagnetic state is very small at the lattice constant a=4.0 Å, and it decreases with increasing the lattice constant. The hyperfine field of the q = (π, π, π) antiferromagnetic state is also rather small at a=4.0 Å, but its magnitude increases considerably with increasing a and at a=4.5 Å it becomes comparable with the hyperfine field of bcc Fe. Furthermore, at a=4.5 Å the q = (π, π, π) antiferromagnetic state is more stable than the ferromagnetic state.