MAGNETIC ORDER IN PALLADIUM-BASED HEUSLER ALLOYS .2. PD2MNIN1-YSBY

Magnetization, susceptibility, X-ray and neutron-diffraction measurements have been on the Heusler alloy series Pd2MnIn1-ySby, for 0 < y < 1. All the alloys were chemically and magnetically ordered with a moment of ≃4.2μB located at the Mn sites. Their magnetic structures change from antiferromagnetic fcc type 2 at the In rich end, to antiferromagnetic fcc type 3A and then to ferromagnetism as the Sb content is increased. The results closely parallel those already reported on the isostructural series Pd2MnIn1-xSnx and Pd2MnSn1-xSbx with the changes in magnetic structures o ccurring at the same conduction electron concentrations. The results strongly support the postulate that the exchange interactions in Heusler alloys are essentially dependent upon the conduction electron concentration. The correlation between the data and an indirect double resonance exchange coupling mechanism is discussed. © 1979.