Graphene‐Based Magnetocaloric Composites for Energy Conversion

Abstract

Herein, a simple, versatile, and cost‐effective method to fabricate innovative thermal conductive magnetocaloric (MC) composites, which offers a smart solution to manufacture active elements with desired geometries, overcoming the current thermal and mechanical limits of the most studied MC materials, is presented. The composite is prepared by embedding powder of a MC material in an epoxy matrix enriched with a graphene‐based material, obtained by thermal exfoliation of graphite oxide. The graphene‐enriched composite shows a significant improvement of the MC time response to the magnetic field, due to the formation of a 3D network that bridges the MC particles and reduces the metal–matrix contact resistance, thus creating a percolation path for an efficient heat transfer. Because of the simplicity and scalability of the preparation method and the great enhancement in response time, these new functional composites represent an important step for the effective application of MC materials in thermomagnetic devices for the energy conversion.

Structural, magnetic and magnetocaloric properties in distorted RE 2NiTiO6 double perovskite compounds

“…As a result, a large number of theoretical and experimental researches have been carried out on a variety of MR materials. Up to now, a series of MR materials with potential application near ambient temperature have been identified, such as Gd-Si-Ge [6], La-Fe-Si/Al [7], Mn-Fe-P-As/Ge/Si [8,9], and Ni-Mn-X (X = Ga, In and Sn) [10,11], etc. In comparison, rare earth (RE)-based compounds and oxides are regarded as the promising cryogenic MR materials for MR technology on account of their unique advantages and application prospects in the liquefaction of extremely low-temperature resources including helium (He), hydrogen (H 2 ) and nitrogen (N 2 ) [12][13][14][15][16].…”