A study of the half-metallic character of the semi Heusler alloys Co1-xCuxMnSb (0??x??0.9) is
presented. We investigated the saturation magnetization MS at temperatures from 5 K to room temperature
and the temperature dependence of the DC magnetic susceptibility ?? above Curie temperature TC. The
magnetic moments at 5 K, for most compositions are very close to the quantized value of 4 ?B for Mn3+
ion, the compound with 90% Co substituted by Cu is still ferromagnetic with MS (5 K)=3.78 ?B/f.u. These
results emphasize the role of Co atoms in maintaining the ferromagnetic order in the material. The Curie
temperature is decreased from 476 K to about 300 K as the Cu content increases from 0% to 90%. Above T
C, the ??-1 vs T curves follow very well the Curie-Weiss law. The effective moment ?eff and paramagnetic
Curie temperature ?? are derived. A comparison between the values of MS at 5 K and ?eff shows a transition
from localized to itinerant spin system in these compounds. ?? 2006 Elsevier B.V. All rights reserved.
