Hyperfine fields at Sn in new ferromagnetic Heusler alloys Co2TiSn, Co2ZrSn and Co2HfSn are studied by means of Mössbauer effect and NMR. The magnitudes and the signs of the hyperfine fields obtained from Mössbauer measurement are +81.6, +88.1 and +106.0 kG at 80 K for Co2TiSn, Co2ZrSn and Co2HfSn respectively. NMR results for Sn nucleus agree with those of Mössbauer effect except for high frequency resonance lines which are probably due to ferromagnetic Co clusters. Moreover a strong NMR signal of Co59 in Co2TiSn at correct lattice sites is found to be +22.2 MHz at 77 K. The results are compared with other Heusler alloys and are discussed about the origin of the hyperfine field at Sn in the alloys based on Blandin and Campbell theory of the spin polarization of conduction electron.
ASJC Scopus subject areas
- Physics and Astronomy(all)