{"id":100456,"date":"2015-03-26T09:21:22","date_gmt":"2015-03-26T13:21:22","guid":{"rendered":"https:\/\/today.uconn.edu\/?p=100456"},"modified":"2015-04-15T11:40:32","modified_gmt":"2015-04-15T15:40:32","slug":"physicists-solve-low-temperature-magnetic-mystery","status":"publish","type":"post","link":"https:\/\/today.uconn.edu\/2015\/03\/physicists-solve-low-temperature-magnetic-mystery\/","title":{"rendered":"Physicists Solve Low-Temperature Magnetic Mystery"},"content":{"rendered":"
\"From<\/a>
From left, Jason Hancock, assistant professor of physics, and fellow researchers Diego Casa and Jung-ho Kim, with one of the instruments used in the experiment. (Argonne National Laboratory Photo)<\/figcaption><\/figure>\n

Researchers have made an experimental breakthrough in explaining a rare property of an exotic magnetic material, potentially opening a path to a host of new technologies. From information storage to magnetic refrigeration, many of tomorrow\u2019s most promising innovations rely on sophisticated magnetic materials, and this discovery opens the door to harnessing the physics that governs those materials.<\/p>\n

The work, led by University of Connecticut professor Jason Hancock, and Ignace Jarrige of the Brookhaven National Laboratory<\/a>, marks a major advance in the search for practical materials that will enable several types of next-generation technology. A paper describing the team’s results is published this week in the journal Physical Review Letters<\/em>.<\/p>\n

The work is related to the Kondo Effect, a physical phenomenon that explains how magnetic impurities affect the electrical resistance of materials. The researchers were looking at a material called ytterbium-indium-copper-four (usually written using its chemical formula: YbInCu4<\/sub>).<\/p>\n

\"Ignace<\/a>
The sample of YbInCu4 used in the experiment. (Brookhaven National Laboratory Photo)<\/figcaption><\/figure>\n

YbInCu4<\/sub>\u00a0has long been known to undergo a unique transition as a result of changing temperature. Below a certain temperature, the material’s magnetism disappears, while above that temperature, it is strongly magnetic. \u00a0This transition, which has puzzled physicists for decades, has recently revealed its secret.\u00a0According to Hancock, the new analysis shows that the material has a gap in its electronic spectrum, similar to the gap found in modern semiconductors.<\/p>\n

Electronic energy gaps define how electrons move (or don\u2019t move) within the material, and are the critical component in understanding the electrical and magnetic properties of materials. \u201cOur discovery goes to show that tailored semiconductor gaps can be used as a convenient knob to finely control the Kondo Effect and hence magnetism in technological materials,\u201d said Jarrige.<\/p>\n

To uncover the energy gap, the team used a process called Resonant Inelastic X-Ray Scattering (RIXS), a new experimental technique that is made possible by an intense X-ray beam produced at a synchrotron operated by the Department of Energy and located at Argonne National Laboratory<\/a> outside Chicago. By placing materials in the focused X-ray beam and sensitively measuring and analyzing how the X-rays are scattered, the team was able to uncover elusive properties such as the energy gap and connect them to the enigmatic magnetic behavior.<\/p>\n

\"RIXS<\/a>
A diagram of the RIXS experiment. (Image by Ignace Jarrige)<\/figcaption><\/figure>\n

The new physics identified through this work suggest a road map for the development of materials with strong \u201cmagnetocaloric\u201d properties, the tendency of a material to change temperature in the presence of a magnetic field.<\/p>\n

\u201cThe Kondo Effect in\u00a0YbInCu4<\/sub> turns on at a very low temperature of 42 Kelvin (-384F),\u201d said Hancock, \u201cbut we now understand why it happens, which suggests that it could happen in other materials near room temperature.\u201d If that material is discovered, he adds, it could revolutionize cooling technology.<\/p>\n

Household use of air conditioners in the U.S. accounts for more than $11 billion in energy costs and releases 100 million tons of carbon dioxide annually. Use of the magnetocaloric effect for magnetic refrigeration as an alternative to the mechanical fans and pumps in widespread use today could significantly reduce those numbers.<\/p>\n

In addition to its potential applications to technology, the work has advanced the state of the art in research. \u201cThe RIXS technique we have developed can be applied in other areas of basic energy science,\u201d said Hancock, noting that the development is very timely, and that it may be useful in the search for \u201ctopological Kondo insulators,\u201d materials that have been predicted in theory, but have yet to be discovered.<\/p>\n","protected":false},"excerpt":{"rendered":"

A breakthrough in explaining a rare property of an exotic magnetic material could lead to new technologies, from information storage to magnetic refrigeration.<\/p>\n","protected":false},"author":77,"featured_media":101148,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_crdt_document":"","wds_primary_category":0,"wds_primary_series":0,"wds_primary_attribution":0,"footnotes":""},"categories":[2076,2227,1],"tags":[],"magazine-issues":[],"coauthors":[183],"class_list":["post-100456","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research","category-uconn-edu-homepage","category-uncategorized"],"pp_statuses_selecting_workflow":false,"pp_workflow_action":"current","pp_status_selection":"publish","acf":[],"publishpress_future_action":{"enabled":false,"date":"2026-05-11 12:10:33","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"category","extraData":[]},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/posts\/100456","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/users\/77"}],"replies":[{"embeddable":true,"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/comments?post=100456"}],"version-history":[{"count":6,"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/posts\/100456\/revisions"}],"predecessor-version":[{"id":101199,"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/posts\/100456\/revisions\/101199"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/media\/101148"}],"wp:attachment":[{"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/media?parent=100456"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/categories?post=100456"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/tags?post=100456"},{"taxonomy":"magazine-issue","embeddable":true,"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/magazine-issues?post=100456"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/today.uconn.edu\/wp-rest\/wp\/v2\/coauthors?post=100456"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}