Electronic structure and the metamagnetic transition of FeSi at extremely high magnetic fields

This is the authors' abstract. We don't add key points for this paper.

A field-induced moment for the narrow-band-gap semiconductor FeSi with a B20-type cubic structure is calculated by a self-consistent linear muffin-tin orbital method within the atomic sphere approximation, by introducing empty spheres in a unit cell. The fixed-spin-moment calculations give two successive metamagnetic transitions. It is found that the first metamagnetic transition will occur at a magnetic field of about 350 T from the nonmagnetic semiconductor to a metallic ferromagnet with a small moment of about 0.1 µ B /Fe. This is consistent with the observed anomaly in the electrical conductivity at about 390 T. The second metamagnetic transition takes place from the small-moment state to a large-moment one with about 1 µ B /Fe at about 700 T. The critical field of the first metamagnetic transition is shown to depend strongly on the value of the band-gap where the Fermi level lies.