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

Abstract 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.