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).

A brilliant cryogenic magnetic coolant: magnetic and magnetocaloric study of ferromagnetically coupled GdF3

“…To date, many gadolinium carboxylates including acetates, formats and oxalates have been reported, with increasing MCE chasing after GGG. [38][39][40][41][42] Since there is little room for the organic ligands to keep shrinking, the most recent focus in this field dramatically returned to the inorganic compounds based on small counterions such as OH -, SO 4 2-, O 2-. [43][44][45] Following the strategies learned in molecular systems, 30-35 significant enhancement of MCE in these inorganic compounds have been observed, and the orthorhombic Gd(OH)CO 3 finally surpass the performance of GGG and set a new record.…”

“…To date, many gadolinium carboxylates including acetates, formates and oxalates have been reported, with increasing MCE chasing after the performance of GGG. [38][39][40][41][42] Since there is little room for organic ligands to keep shrinking, the most recent focus in this field dramatically returned to inorganic compounds based on small counterions such as OH À , SO 4…”

Wheel-like Gd42 polynuclear complexes with significant magnetocaloric effect

“…This can be achieved through the premeditated choice of suitable ligands with small molecular mass with multiple coordination sites, which either meet the high coordination number requirement of the central 4f ions or improve metal ion mass concentrations. 11 Many studies reported that Gd-based clusters bridged by sulfates, 12 oxalates, 13 carbonates, 14 carboxylates, 15 etc. usually result in weak magnetic interactions, since these anions normally constrain the magnetic coupling between Gd 3+ ions.…”

Band gap and pseudocapacitance of Gd2O3 doped with Ni0.5Zn0.5Fe2O4

“…The Gd 3+ ion carries a large spin magnetic moment (S = 7/2) which makes the gadolinium-based composite materials interesting [1]. They have found their applications in a variety of fields including magnetic coolers [2], high-performance conductors [3], supercapacitors electrodes [4], optoelectronics [5], and magnetic resonance imaging(MRI) [6,7]. A very recent review report has highlighted the spintronic potential of the Gd 3+ composites in the ferroic-order [ferromagnetic, ferroelectric, and multiferroic] oxides [8].…”