Magnetocaloric Effect in 3D Gd(III)-Oxalate Coordination Framework
Fang-Wen Lv1, Mei-Xin Hong1, Xue-Ting Wang1
1Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, School of Materials Science and Engineering, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China.
Abstract:
Cryogenic magnetic refrigerants based on the magnetocaloric effect (MCE) hold significant potential as substitutes for the expensive and scarce He-3. Gd(III)-based complexes are considered excellent candidates for low-temperature magnetic refrigerants. We have synthesized a series of Ln(III)-based metal-organic framework (MOF) Ln-3D (Ln = Gd/Dy) by the slow release of oxalates in situ from organic ligands (disodium edetate dehydrate (EDTA-2Na) and thiodiglycolic acid). Structural analysis shows that the Ln-3D is a neutral 3D framework with one-dimensional channels connected by [Ln(H2O)3]3+ as nodes and C2O42- as linkers. Magnetic measurements show that Gd-3D exhibits very weak antiferromagnetic interactions with a maximum -ΔSm value of 36.6 J kg-1 K-1 (-ΔSv = 74.47 mJ cm-3 K-1) at 2 K and 7 T. The -ΔSm value is 28.4 J kg-1 K-1 at 2 K and 3 T, which is much larger than that of commercial Gd3Ga5O12 (GGG), indicating its potential as a low-temperature magnetic refrigerant.
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