Pressure dependence of temperature variation of AC susceptibility for Fe50Ni37Mn13 and comparison to Fe68.1Ni31.9

Fe50Ni37Mn13, which is a ferromagnetic alloy with FCC crystal structure, has been reported to show the Invar effect below the Curie temperature; however, this alloy shows a typical anti-Invar effect above the Curie temperature. In this paper, we discuss the pressure dependence of the temperature variation of the alternative current (AC) susceptibility at a frequency of 1 kHz for Fe50Ni37Mn13 at various pressures up to 7.5 GPa above 77 K; we then compare the results with those for Fe68.1Ni31.9, which were obtained in a previous study. Fe50Ni37Mn13 was in a ferromagnetic state throughout the entire pressure range measured. TC decreases in inverse proportion to the increasing pressure; dTC/dp and dln TC/dp for Fe50Ni37Mn13 are -26 K GPa-1 and -0.07 GPa-1, respectively. Further, the temperature variation of the shape of the χ'-T curve for different pressures indicates continuous combining of magnetic interactions occurs at high pressures. These results are similar to those obtained for Fe68.1Ni31.9