NMR properties of half-Heusler CoVSb

The complex NMR properties of CoVSb are reported. On the basis of band structure calculations the compound is predicted to be a half metallic ferromagnet but magnetisation measurements suggest that the compound is a weak ferromagnet. In zero applied field at 4.2 K, three spin echo signals have been observed with peak frequencies of 30, 63 and 82 MHz, which are tentatively assigned as signals associated with antimony, vanadium and cobalt atoms. The cobalt atoms are suggested to have moments of about 0.8 μB. In addition three spin echo signals have been observed in swept applied fields at 4.2 K which include signals from non magnetic cobalt and vanadium sites. Thus weak ferromagnetism in CoVSb is concluded to be complex on a microscopic scale with the moment of 0.18 μB per formula unit, obtained from static magnetic measurements, being the average moment of magnetic and nonmagnetic sites of cobalt and vanadium atoms. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)