The57Fe Mössbauer spectra of the Fe-Ni 36 wt.% Invar alloy at different temperatures (300-530 K) have been measured. The experimental results indicate that the hyperfine field distributions are characterized by dual peaks. The temperature dependence of the hyperfine field indicates that some iron atoms may transfer from the ferromagnetic state to the antiferromagnetic one with increasing temperature, and that the variation of the ratio of number N0 of the iron atoms in the antiferromagnetic state to the number Nh in the ferromagnetic state with temperature will obey the thermodynamic relationship.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics
- Condensed Matter Physics
- Physical and Theoretical Chemistry