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Published on: March 30, 2017
Gd(OH)F2: A Promising Cryogenic Magnetic Refrigerant
Qiaofei Xu1, Boliang Liu1, Mingyu Ye1
1Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
Researchers developed new magnetic refrigerants for adiabatic demagnetization refrigeration. These materials exhibit a large magnetocaloric effect (MCE) at low temperatures, improving cooling efficiency.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Thermodynamics
Background:
- Adiabatic demagnetization refrigeration requires magnetic refrigerants with a large magnetocaloric effect (MCE) over a wide temperature range and low magnetic ordering temperatures (To) in the sub-kelvin region.
- Developing such materials is challenging due to the need for low To, weak magnetic interactions, and high magnetic density.
Purpose of the Study:
- To synthesize and characterize novel magnetic refrigerants based on Gd(OH)3-xFx.
- To investigate the effect of fluoride anion incorporation on the magnetic properties and MCE of gadolinium hydroxide.
Main Methods:
- Synthesis of Gd(OH)3-xFx compounds (x = 1, ≈1.5, 2).
- Measurement of heat capacities and magnetic properties.
- Analysis of magnetocaloric effect (MCE) in the sub-kelvin temperature range.
Main Results:
- The introduction of fluoride anions into antiferromagnetic Gd(OH)3 effectively regulated its magnetic ordering temperature (To).
- Compound 3 (Gd(OH)1.5F2) exhibited a To of 0.5 K.
- Compound 3 demonstrated a large MCE in the 0.5–4 K temperature range.
Conclusions:
- Gd(OH)3-xFx compounds represent a promising class of magnetic refrigerants for sub-kelvin cooling applications.
- Compound 3 is identified as the best magnetic refrigerant reported to date for the 0.5–4 K range based on MCE.
- Fluoride incorporation offers a viable strategy for tuning To and enhancing MCE in magnetic refrigerants.
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