Magnetocaloric properties of the hexagonal HoMnO3 single crystal revisited

Magnetic and magnetocaloric properties of the hexagonal HoMnO3 single crystal have been revisited. It was found that the magnetocaloric effect shown by HoMnO3 strongly depends on the crystal orientation in respect to the applied magnetic field. Consequently, a large thermal effect can be induced by spinning the single crystal HoMnO3 around the a (or b) axis in a constant magnetic field instead of the conventional magnetization–demagnetization process. Under 7 T, the maximum rotating entropy change was evaluated to be about 8 J/kg K. The associated adiabatic temperature change reaches a value of about 5 K. These values are comparable to those of the other oxides exhibiting a large rotating magnetocaloric effect. The presence of both conventional and rotating thermal effects makes the hexagonal HoMnO3 more interesting from a practical point of view.