High-efficiency magnetic refrigeration using holmium.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33608549.
- Also identified by DOI 10.1038/s41467-021-21234-z and PMC identifier 7896054.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Magnetic refrigeration (MR) is a method of cooling matter using a magnetic field. Traditionally, it has been studied for use in refrigeration near room temperature; however, recently MR research has also focused on a target temperature as low as 20 K for hydrogen liquefaction. Most research to date has employed high magnetic fields (at least 5 T) to obtain a large entropy change, which requires a superconducting magnet and, therefore, incurs a large energy cost. Here we propose an alternative highly efficient cooling technique in which small magnetic field changes, Δμ<sub>0</sub>H ≤ 0.4 T, can obtain a cooling efficiency of -ΔS<sub>M</sub>/Δμ<sub>0</sub>H = 32 J kg<sup>-1</sup>K<sup>-1</sup>T<sup>-1</sup>, which is one order of magnitude higher than what has been achieved using typical magnetocaloric materials. Our method uses holmium, which exhibits a steep magnetization change with varying temperature and magnetic field. The proposed technique can be implemented using permanent magnets, making it a suitable alternative to conventional gas compression-based cooling for hydrogen liquefaction.