The alloy may prove to be a long-sought material that will permit magnetic cooling instead of the gas-compression systems used for home refrigeration and air conditioning. The magnetic cooling technique, though used for decades in science and industry, has yet to find application in the home because of technical and environmental hurdles—but the NIST collaboration may have overcome them.
Magnetic cooling relies on materials called magnetocalorics, which heat up when exposed to a powerful magnetic field. After they cool off by radiating this heat away, the magnetic field is removed, and their temperature drops again, this time dramatically. The effect can be used in a classic refrigeration cycle, and scientists have attained temperatures of nearly absolute zero this way. Two factors have kept magnetic cooling out of the consumer market: most magnetocalorics that function at close to room temperature require both the prohibitively expensive rare metal gadolinium and arsenic, a deadly toxin.But conventional gas-compression refrigerators have their own drawbacks. They commonly use hydrofluorocarbons (HFCs), greenhouse gases that can contribute to climate change if they escape into the atmosphere. In addition, it is becoming increasingly difficult to improve traditional refrigeration. “The efficiency of the gas cycle has pretty much maxed out,” said Jeff Lynn of NCNR. “The idea is to replace that cycle with something else.”
Working alongside (and inspired by) visiting scientists from the Beijing University of Technology, the team used NIST’s neutron diffraction equipment to analyze the novel alloy. They found that when exposed to a magnetic field, the newfound material’s crystal structure completely changes, which explains its exceptional performance.
“Understanding how to fine-tune this change in crystal structure may allow us to get our alloy’s efficiency even higher,” says NIST crystallographer Qing Huang. “We are still playing with the composition, and if we can get it to magnetize uniformly, we may be able to further improve the efficiency.”
* D. Liu, M. Yue, J. Zhang, T.M. McQueen, J.W. Lynn, X. Wang, Y. Chen, J. Li, R.J. Cava, X. Liu, Z. Altounian and Q. Huang. Origin and tuning of the magnetocaloric effect for the magnetic refrigerant MnFe(P1-xGex). Physical Review B. Vol. 79, 014435 (2009)
Members of the collaboration include scientists from NIST, Beijing University of Technology, Princeton University and McGill University. Funding for the project was provided by NIST.
Chad Boutin | EurekAlert!
Further reports about: > Huang > NIST > air conditioning > classic refrigeration cycle > consumer market > crystal structure > electricity-guzzling cooling system > exotic metal > gas-compression systems > greenhouse gas > home refrigeration > hydrofluorocarbons > magnetic cooling > magnetic cooling technique > magnetic field > magnetocalorics > material’s crystal structure > powerful magnetic field > refrigerator’s humming
Electrocatalysis can advance green transition
23.01.2017 | Technical University of Denmark
Quantum optical sensor for the first time tested in space – with a laser system from Berlin
23.01.2017 | Ferdinand-Braun-Institut Leibniz-Institut für Höchstfrequenztechnik
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Health and Medicine
23.01.2017 | Physics and Astronomy
23.01.2017 | Process Engineering