Low temperature magnetic properties of F.C.C. FeCrNi alloys: Effects of manganese and interstitial carbon and nitrogen

We have measured the low temperature magnetic susceptibility of two series of f.c.c. FeCrNi alloys: one series contained varied amounts of interstitial carbon and nitrogen; the other contained varied amounts of manganese. Characteristic of antiferromagnets, all specimens displayed a distinct peak in magnetic susceptibility as a function of temperature. Above the transition temperature the behavior of all specimens could be well described by a modified Curie-Weiss law x= x o C T+θ In the first series the position of the susceptibility maximum decreased from 47.9 ± 0.5 to 35.0 ± 0.5 K as the carbon-plus-nitrogen content increased from 0.080 to 0.359 wt. %. In the second series the position of the susceptibility maximum increased from 46 ± 0.5 to 86.5 ± 0.5 K as the manganese content was increased from 1.02 to 5.80 wt.%. A linear relationship was found to predict the Néel temperature from the alloy composition with an r.m.s. deviation of 1 K.