SPIN POLARIZATION IN V(001) SLABS

We discuss the onset of layered antiferromagnetic structure in very thin V(001) slabs in terms of the exchange integral J. We use a self-consistent real-space tight-binding method in the unrestricted Hartree-Fock approximation to the Hubbard Hamiltonian. Antiferromagnetic structures occur more readily, i.e. at smaller J values, than ferromagnetic structures. When both paramagnetic and antiferromagnetic solutions are present (for a J value greater than a critical value J(c)), the layered antiferromagnetic solutions are always stable. The bilayer is found to be antiferromagnetically polarized; for three layer slabs two types of antiferromagnetic solution are obtained. Our results display the variety of possible magnetic behavior in metallic films and give some insight into the controversial situation on V(001) surface.