On the rotating magnetocaloric effect in multiferroic RMn2O5 compounds.

Thanks to the strong magnetic anisotropy shown by RMn2O5 compounds, a large magnetocaloric effect can be induced (around 10 K) by rotating them in constant magnetic fields instead the standard magnetization-demagnetization method. Particularly, the TbMn2O5 single crystal reveals a giant rotating magnetocaloric effect (RMCE) under relatively low constant magnetic fields reachable by permanent magnets. On the other hand, it was found that the RMCE in RMn2O5 crystals strongly depends on the R3+ ion nature. Under a constant magnetic field of 2 T, the maximum rotating adiabatic temperature change exhibited by TbMn2O5 is
more than 5 times larger than that presented by HoMn2O5. The rare earth ion size could play a crucial role in the determination of the magnetic and magnetocaloric properties of RMn2O5 compounds through the modulation of exchange interactions via lattice distortions, a scenario that seems to be supported by Raman scattering.