Anomalies in specific heat and thermal expansion of FCC iron alloys

Abstract

Measurements of the specific heat of FCC iron alloys reveal Schottky anomalies in the paramagnetic temperature range with the same excitation energies of about 0.1 eV that have been used in a preceding paper to describe the anomalies in thermal expansion. Magnetically ordered Fe-Ni alloys also reveal anomalies in specific heat which can be described by assuming a splitting of the degenerate energy levels caused by the magnetic coupling. The same model is also capable of describing the invar effect occurring in these alloys in a quantitative manner.