In this paper, the influence of the Mn content on the magnetocaloric response of ribbon-shaped amorphous samples of Fe80-xMn xB20 (x=10, 15, 18, 20, and 24), has been studied. For this purpose, the temperature and field dependence of the magnetic entropy change (Δ SM) have been obtained from magnetization curves. The partial substitution of Fe by Mn leads to a monotonous change in the Curie temperature (TC) of the alloys from 438 K for x=10 to 162 K for x=24, in agreement with the coherent-potential approximation. These Curie temperatures could make them good candidates to be used for magnetic refrigeration at room temperature. For an applied field of 1.5 T, the maximum entropy change (Δ SMpk) passes from 1 J K -1 kg-1 (x=10) to 0.5 J K-1 kg-1 (x=24), and the refrigerant capacity varies between 117 J kg-1 (x=10) and 68 J kg-1 (x=24). A linear relationship between Δ S Mpk and the average magnetic moment per transition metal atom (〈μ〉Fe,Mn) has been presented.
ASJC Scopus subject areas
- Physics and Astronomy(all)