Magnetic properties of Tb12Co7

The magnetic properties of the compound Tb12Co7 with the Ho12Co7-type monoclinic structure were investigated from 5 to 300 K in applied magnetic fields up to 5 T. The field-cooled and zero-field-cooled magnetization curves of Tb12Co7 measured at low field and at low temperatures exhibit different behavior, which is due to the temperature-dependent coercivity. The ferromagnetic-paramagnetic transition temperature in a field of 0.01 T is about 100 K. At 5 K, the saturation magnetization and the coercivity are 165 A m2 kg-1 and 0.18 T, respectively. The maximum magnetic-entropy change, vertical bar ΔS M vertical bar, of Tb12Co7 is 3.08 J kg-1 K-1 at 100 K for a field change of 2 T, which is comparable to that of rare-earth perovskite manganites series La1-x M x MnO3