A Mossbauer determination of the magnitude and sign of hyperfine fields at119Sn nuclei in Heusler alloys

Abstract

Using the Mossbauer effect in ¹¹⁹Sn the hyperfine fields at the Sn sites in the Heusler alloys X₂MnSn (where X is Cu, Co, Pd and Ni) have been measured at 10K to be +196, +105, -38 and +95 kG respectively. The signs were determined unambiguously using circularly polarized gamma rays. These values of the fields at the X sites (where known) and the Curie temperatures, can be explained on the basis of a resonance scattering theory, provided the numbers of conduction electrons/atom are not restricted to those derived from simple valence considerations.