Large anisotropic magnetocaloric effect of MnP alloy: A theoretical study

Magnetocaloric effect has attracted great attention as a promising method for future refrigeration with high power and efficiency. The conventional magnetocaloric materials are heated up or cooled down by applying or removing an external magnetic field. On the other hand, the temperature of a rotating magnetocaloric system can be modified by changing the direction of the external magnetic field. Several rotating magnetocaloric materials have been reported in the previous experimental works, motivating us to study the rotating magnetocaloric effect in a theoretical framework. The rotating magnetocaloric effect of MnP is studied by combining first-principles calculations and Monte-Carlo simulations. The magnetocrystalline anisotropy energy is not negligible even above the Curie temperature due to the effect of the magnetic field. The dependence of the isothermal magnetic entropy change on the direction is calculated with the Maxwell relation [1-2]. The magnetic entropy changes by rotating the sample are reasonably predicted and underlying mechanisms for the effect are discussed in detail.
[1] H. B. Tran, T. Fukushima, K. Sato, Y. Makino, and T. Oguchi, J. Alloys Compd. 854, 157063 (2021).
[2] H. B. Tran, T. Fukushima, Y. Makino, and T. Oguchi, Solid State Commun. (2020). Accepted