Energetic comparison of rotation and translation processes in magnetic refrigeration

Conventional magnetic refrigeration relies on removing a magnetic refrigerant from a magnetic field to induce demagnetization and an adiabatic change in temperature. An emerging alternative, the demagnetizing field-induced magnetocaloric effect (dRMCE), achieves cooling by rotating a shape-anisotropic refrigerant, using changes in the demagnetizing field instead of physical displacement. A key advantage of this approach is its potential for higher energetic efficiency due to reduced work input. This study evaluates that claim by numerically com- paring the magnetic work and heat generation in dRMCE and conventional magnetocaloric effect (MCE). Using finite element analysis, we simulate the demagnetizing field of a thin polycrystalline gadolinium plate in both processes, tracking step-by-step energy changes. Our results demonstrate that, despite producing a smaller adiabatic temperature change (DT) and less isothermal heat, the dRMCE consistently outperforms conventional MCE in heat-per-work efficiency, exhibiting 20%–80% higher efficiency in isothermal demagnetization and 40%– 80% higher efficiency in adiabatic demagnetization (followed by isomagnetic heating).