Specific heat capacity of Fe3-xMnxSi compounds

Abstract

The specific heat capacities over the temperature range 4-460K are reported for Fe3-xMnxSi compounds with x=0.6, 0.8, 1.0, 1.2 and 1.6. No gross features associated with the onset of the ferromagnetism of these compounds are found. Evidence of broad anomalies, which may be related to the ferromagnetic order is seen in the x=0.6 and 0.8 compounds. Small features in the specific heat capacity close to the ferromagnetic ordering temperatures for the x=1.0, 1.2 and 1.6 compounds are resolved as 'step-like' anomalies using data for the x=0.6 and 1.6 compounds as a background correction. Distinct cusp-shaped peaks are found at the magnetic re-ordering temperature for these compounds. Estimates of the magnetic entropy associated with the magnetic ordering indicate that the re-ordering process plays a major role in the establishment of the magnetic ground-state.