Magnetocaloric properties of Gd in fields up to 14Â T

The magnetocaloric effect (MCE) of polycrystalline gadolinium was studied in high steady magnetic fields up to 14 T by direct measurements of the adiabatic temperature change (ΔT) using an “extraction method”. Large MCE was observed at the ferromagnetic phase transition resulting in ΔT of 19.5 K at a field change of 14 T. The direct measurements of MCE were performed using the measuring system designed and constructed by the authors. It was shown that near the Curie temperature, the magnetic field dependence of the adiabatic temperature change is far from saturation even in a 14 T field and is adequately described by the thermodynamic Landau theory for magnetic second-order phase transitions.