Magnetic transitions in bcc vanadium, chromium, manganese, and iron

Abstract

We have examined the transition from nonmagnetic to ferromagnetic behavior for elemental bcc vanadium, chromium, manganese, and iron by analyzing self-consistent parameter-free total-energy band-structure calculations in the local-spin-density approximation utilizing a fixed-spin-moment procedure. All systems are found to exhibit singular behavior and to undergo complex transitions as a function of volume. For each system, we find a set of critical Wigner-Seitz radii rWS defining the onset of magnetic behavior and the end of nonmagnetic behavior. Vanadium and manganese exhibit composite (second-order and first-order) transitions with nonmagnetic low-spin and high-spin magnetic behavior. Chromium undergoes a first-order transition from nonmagnetic to magnetic behavior at expanded volumes, and iron undergoes a second-order transition and becomes nonmagnetic at reduced volumes. © 1988 The American Physical Society.