Magnetic cryocooling with Gd3+ centers in a light and compact framework

TL;DR

This study investigates gadolinium formate's magnetocaloric properties at sub-Kelvin temperatures, demonstrating its potential as a lightweight, compact magnetic refrigerant with superior volumetric entropy change compared to existing materials.

Contribution

It provides the first experimental characterization of Gd(OOCH)3's magnetocaloric effect at very low temperatures, highlighting its structural advantages for cryocooling applications.

Findings

Gd(OOCH)3 exhibits a large magnetic entropy change at sub-Kelvin temperatures.

The material's lightweight and compact framework enhances volumetric efficiency.

Gd(OOCH)3 outperforms existing magnetic refrigerants in low-temperature regimes.

Abstract

The magnetocaloric effect of gadolinium formate, Gd(OOCH)3, is experimentally determined down to sub-Kelvin temperatures by direct and indirect methods. This 3D metal-organic framework material is characterized by a relatively compact crystal lattice of weakly interacting Gd3+ spin centers interconnected via light formate ligands, overall providing a remarkably large magnetic:non-magnetic elemental weight ratio. The resulting volumetric magnetic entropy change is decidedly superior in Gd(OOCH)3 than in the best known magnetic refrigerant materials for liquid-helium temperatures and low-moderate applied fields.