Une nouvelle découverte dans les métaux magnétiques pourrait conduire à des améliorations dans le froid magnétique (en anglais)

Des scientifiques ont récemment résolu le mystère concernant une propriété distincte d'un métal magnétique unique. Cette découverte pourrait ouvrir la voie au développement de plusieurs nouvelles technologies dans le domaine du froid magnétique.
Scientists from the University of Connecticut, USA, in collaboration with other researchers, have recently solved the mystery behind a distinct property in a unique magnetic metal. Ultimately this discovery could pave the way for the development of several new technologies such as more practical magnetic refrigeration and improved cooling systems for Magnetic Response Imaging (MRI) systems.

The research was in collaboration with Brookhaven National Laboratory and it was led by UConn Assistant Professor of Physics Jason Hancock and Brookhaven researcher Dr. Ignace Jarrige.

The investigation dealt primarily with the Kondo effect, which describes how magnetic impurities lead to scattering of electrons in different metals in response to changes in temperature. The material which was studied was ytterbium-indium-copper-four (YbInCu4), which has unique properties related to how its magnetism radically changes in response to a certain temperature.
Using a groundbreaking synchrotron based analysis technique, researchers were able to prove that the cause of the switching behavior observed in YbInCu4 is caused by gaps in its energy spectrum.

Despite not being intentioned as applied research, the insight gained through the understanding of this unique property could ultimately lead to the development of several future technologies. Particularly, it could eventually lead to improvements in magnetic refrigeration techniques.

The magnetic change associated with the Kondo effects occurs at a very low temperature (42K or -231°C) for YbInCu4, which makes this particular material impractical for commonplace refrigeration techniques. However, the insight into the cause of the observed switching behavior may allow researchers to discover materials where the switching occurs much closer to room temperature.