Large relative cooling power arising from consecutive magnetic phase transitions in van der Waals CrSBr

Two-dimensional (2D) van der Waals magnets are promising for low-dimensional solid-state refrigeration, but their relative cooling power (RCP) is often limited by modest magnetic entropy changes. Here, we show that CrSBr single crystals undergo successive three-step magnetic transitions, which broaden the working temperature window as magnetic refrigerant. This multistep behavior, combined with in-plane anisotropy along the b axis, yields a maximum magnetic entropy change of 4.9 J kg−1 K−1 under 7 T and a large RCP of 273.68 J kg−1 at 5 T, surpassing most reported 2D magnets. Critical scaling analysis reveals tricritical mean-field behavior near the intralayer ferromagnetic–paramagnetic transition. These results demonstrate that multistep transitions provide an effective route to enhance refrigeration efficiency, establishing CrSBr as a high-performance 2D magnetic refrigerant.