Magnetocaloric properties of Gd6(Mn1−xFex)23 alloys (x≤0.2)(x≤0.2)

The Curie temperature of the Gd6(Mn1−xFex)23 (x≤0.2x≤0.2) ferrimagnets evolves with the Fe content from TC=489K for x=0.0x=0.0 down to TC=176K for x=0.2x=0.2. The Fe for Mn substitution also yields a decrease of the maximal magnetization recorded at 5 K in a 9 T magnetic field (54.7μB/f.u. and 42.0μB/f.u. for x=0.0x=0.0 and x=0.2x=0.2, respectively). These alloys present an anomalous magnetocaloric effect. The magnetocaloric response extends over a broad temperature interval from TCTC down to the lowest temperatures, with two −ΔSM maxima of moderate magnitude at TCTC and near 100 K. This yields a large cooling capacity q∼3.3J/cm3 for μ0ΔH=5T.