Giant low-field magnetocaloric effect in hexagonal Eu3B2O6 compound

A modified solid-phase reaction method was used to synthesize the polycrystalline Eu3B2O6-as a novel cryogenic magnetocaloric material. In addition, investigations into the magnetocaloric effect (MCE), mag-netic properties and crystal structure of compound have been precisely completed. The results indicate that the compound undergoes a second-order magnetic-phase transition from ferromagnetic to paramagnetic at 8 K and has a hexagonal structure that belongs to the R-3c space group. Meanwhile, the MCE was evaluated by using magnetic entropy change (-Delta SM), temperature averaged entropy change (TEC) as well as the re-frigeration capacity (RC) for Eu3B2O6. Under the field change from 0 to 5 T, the maximal values of-Delta SM and TEC (5) are 38.6 and 35.7 J kg-1 K-1, respectively, while the corresponding RC reaches 435.9 J kg-1. The giant low-field MCE facilitates device miniaturization and cost reduction, making Eu3B2O6 compound a promising candidate for cryogenic magnetic refrigeration.(c) 2022 Published by Elsevier B.V.

Automated summary

A modified solid-phase reaction method was used to synthesize polycrystalline Eu3B2O6 as a novel cryogenic magnetocaloric material. The magnetocaloric effect, magnetic properties, and crystal structure of the compound were investigated. The compound undergoes a second-order magnetic-phase transition from ferromagnetic to paramagnetic at 8 K and has a hexagonal structure belonging to the R-3c space group. The compound exhibits a high magnetic entropy change, temperature averaged entropy change, and refrigeration capacity, making it a promising candidate for cryogenic magnetic refrigeration.