Improved Magnetocaloric Effects in Alfe2b2 Intermetallics Through the Enhancement of Magnetoelastic Coupling

The development of high-performance magnetocaloric material is one of the keys to actualize the room-temperature magnetic refrigeration technology. Here the effects and mechanisms of solidification behaviors and microstructures on the magnetocaloric effect (MCE) of AlFe 2 B 2 intermetallics are investigated. The solidification behaviors of Al x Fe 2 B 2 (x=1.0, 1.2, 1.4, 1.6, and 1.8) were regulated via controlling the content of Al elements, that is, peritectic reaction for x < 1.4 and direct crystallization for x ≥ 1.4. The magnetic entropy changes under an applied magnetic field of 5 T of AlFe 2 B 2 intermetallics prepared by peritectic reaction can reach 7.2 J kg -1 K -1 near room-temperature, which is much larger than that of direct crystallization samples (~5 J kg -1 K -1 ). The reason is attributed to the abrupt change of crystal cells and its effect on the magnetoelastic coupling. The present work provides a new perspective to accurately control the MCE of AlFe2B2 phase, which is beneficial for its further practical application