Band model for the metal-semiconductor transition in NiS
Abstract
A simplified form of Slater's model for treating exchange effects in an itinerant antiferromagnet is applied to hexagonal NiS. In this calculation, which involves the augmented-plane-wave (APW) method, the antiferromagnetic superlattice is introduced by adding a constant +Vs and -Vs to the potentials within the two nickel APW spheres in the nonmagnetic unit cell. It is found that this superlattice opens a narrow band gap at the NiS Fermi level when Vs~0.04 Ry. As a result, we conclude that the observed low-temperature nonmetallic behavior in NiS is due to the antiferromagnetic superlattice and does not involve a Mott-Hubbard transition.
- Publication:
-
Physical Review B
- Pub Date:
- August 1974
- DOI:
- 10.1103/PhysRevB.10.995
- Bibcode:
- 1974PhRvB..10..995M