On the cross-over from half-metal to normal ferromagnet in NiMnSb
Laboratoire de Magnétisme Louis Néel, CNRS, 166X,
38042 Grenoble Cedex 9, France
Published online: 15 July 2000
Magnetism and transport properties of the semi-Heusler compound NiMnSb are re-examined in great details. A wide set of experiments (elastic and inelastic neutron scattering, static magnetic measurements, magnetoresistance, Hall effect, thermopower, FMR) have been performed on polycrystals, single crystals or single-crystalline thin films, and the results are analysed. Special emphasis is given to the magnetic excitations and to the relaxation mechanisms in this metallic ferromagnet. At low temperatures, all experimental results hint at the existence of a fully spin-polarized conduction band (half metallic state). At higher temperature (T > 80 K), but well below the Curie temperature (730 K), a cross-over to a usual metallic ferromagnetic state is evidenced and discussed.
PACS: 75.50.Cc – Other ferromagnetic metals and alloys / 72.15.Gd – Galvanomagnetic and other magnetotransport effects / 76.50.+g – Ferromagnetic, antiferromagnetic, and ferrimagnetic resonances; spin-wave resonance
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000