Structure and properties of GdAuSn and the GdAuSn/MnAuSn system

The crystal structure of GdAuSn was refined by means of single crystal X-ray diffraction. Band structure calculations based on the structural data confirmed the aritiferromagnetic ground state and the metallic behaviour of GdAuSn. Sn-119m, Gd-155 and Au-197 Mossbauer spectroscopic studies were used to verify the values of the hyperfine parameters that were given by the band structure calculations. Band structure calculations of MnAuSn confirmed that this half-Heusler compound belongs to the family of half-metallic ferromagnets. Magnetic susceptibility, conductivity and Mossbauer studies were used to characterize granular material based on the half-Heusler ferromagnet MnAuSn in the antiferromagnetic GdAuSn matrix. Magnetoresistance measurements of the granular systems revealed an enormously high positive effect at temperatures below the antiferromagnetic ordering in GdAuSn.