Thermodynamics of the Heat-Flux Avalanches at the First-Order Magnetic Transition in Magnetocaloric Materials

Quiet, efficient, coolant-free magnetic refrigeration could be the technology of the future, but for now it still presents challenges, even at the level of plain physics. For example, understanding the kinetics of first-order phase transitions in magnetocaloric compounds is key to improving the operating frequency of magnetic cooling devices. The authors measure these transitions and analyze them, in terms of nonequilibrium thermodynamics and the heterogeneous nucleation and pinning of magnetic phases at crystallographic defects. Their insight should be helpful in selecting optimal working materials for such applications.