Thermal energy harvesting with magnetocalorics

Cutting greenhouse emissions, and improving the global energy efficiency have been the main goals of researches in the field of caloric materials for more than two decades now (1). So far, the research of new solid state cooling devices, using magnetocalorics (MC) as re- frigerant, has been primarily focused on achieving better efficiency (2). Recently, a growing attention to other energy conversion applications with some emphasis on the micro and nano scales has triggered a paradigm shift towards energy harvesting (3). Here, we shall briefly review the main scientific, and technological challenges entailed by switching from cooling to thermo-magnetic generation (TMG) focusing on the modeling tools used to study the effi- ciency/power trade-of. Some recent results obtained using Gd films as the active substance in a TMG, microscale device will be presented (4). and present some recently developed TMG prototypes and their properties. (1) X. Moya, S. Kar-Narayan, and D. Mathur Neil, Caloric Materials Near Ferroic Phase Transitions, Nat. Mater. 13, 439 (2014). (2) J. Lyubina, Magnetocaloric materials for energy efficient cooling, J. Phys. D: Appl. Phys. 50, 053002 (2017) (3) A. Kitanovski, Energy applications of magnetocaloric materials, Adv. Energy Mater. 10, 1903741 (2020) (4) ) D. Nguyen Ba, Y. Zheng, L. Becerra, m. marangolo, M. Almanza, and M. LoBue, Mag- netocaloric Effect in Flexible, Free-Standing Gadolinium Thick Films for Energy Conversion Applications, Physical Review Applied 15, (2021)