Magnetocaloric effect in gadolinium-oxalate framework Gd2(C2O4)3(H2O)6·(0.6H2O)

Abstract

Magnetic refrigerants incorporating Gd3+ ions and light organic ligands offer a good balance between isolation of the magnetic centers and their density. We synthesized the framework material Gd2(C2O4)3(H2O)6·0.6H2O by a hydrothermal route and characterized its structure. The honeycomb lattice of Gd3+ ions interlinked by oxalate ligands in the (a,c) plane ensures their decoupling in terms of magnetic exchange interactions. This is corroborated by magnetic measurements indicating negligible interactions between the Gd3+ ions in this material. The magnetocaloric effect was evaluated from isothermal magnetization measurements. The maximum entropy change -ΔSMmax reaches 75.9 mJ cm-3 K-1 (around 2 K) for a moderate field change (2 T).