Magnetic hyperfine fields in the Heusler alloys Co2 YZ (Y=Sc,Ti, Hf,V, Nb; Z=Al,Ga, Si,Ge, Sn)

The magnetic hyperfine field acting on Ta at the non-magnetic transition element site has been investigated in the Heusler alloys Co₂(Sc, Hf, V)Sn, Co₂ScGa, Co₂(V, Nb)Al and Co₂Ti(Si, Ge) by TDPAC measurements utilizing the 133–482 keV gamma-gamma cascade in¹⁸¹Ta following the ^– decay of¹⁸¹Hf. An important conclusion is that the reduced mhf either on the non-magnetic transition element site or on the s-p element site depends mainly on the chemical nature of the non-magnetic transition element rather than any other factor, e.g. the local moment _Co of the alloy.Supported by a fellowship from CNPq.Supported by a fellowship from FAPESP.