{"id":3562,"date":"2022-01-27T16:36:15","date_gmt":"2022-01-27T21:36:15","guid":{"rendered":"https:\/\/my.vanderbilt.edu\/vinsenews\/?p=3562"},"modified":"2022-01-27T16:36:16","modified_gmt":"2022-01-27T21:36:16","slug":"research-snapshot-breakthrough-measurementstheory-of-vibrating-atoms-in-nanostructures-ushers-in-new-class-of-technology","status":"publish","type":"post","link":"https:\/\/my.vanderbilt.edu\/vinsenews\/2022\/01\/research-snapshot-breakthrough-measurementstheory-of-vibrating-atoms-in-nanostructures-ushers-in-new-class-of-technology\/","title":{"rendered":"Research Snapshot: Breakthrough measurements\/theory of vibrating atoms in nanostructures ushers in new class of technology"},"content":{"rendered":"
\n

Vanderbilt researchers\u00a0<\/span>Sokrates Pantelides<\/span><\/a>\u00a0and\u00a0<\/span>Joshua Caldwell<\/span><\/a>\u00a0are part of an international collaboration that has demonstrated a new\u00a0way\u00a0to manipulate and measure\u00a0subtle atomic vibrations\u00a0in\u00a0nanomaterials.\u00a0This breakthrough\u00a0could make it possible\u00a0to develop customized functionalities\u00a0to improve\u00a0on and build new\u00a0technologies.<\/span>\u00a0<\/span><\/p>\n

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Sokrates Pantelides\u00a0<\/figcaption><\/figure>\n
\"Joshua
Joshua Caldwell\u00a0<\/figcaption><\/figure>\n

Electron beams in powerful microscopes have probed materials and nanostructures with atomic-scale resolution, imaged the atomic arrangements and, in combination with theory, unveiled electronic and magnetic properties. Recent developments in microscopy help make it possible to get direct signals from phonons, namely vibrational modes, with high resolution in both space and energy. Researchers can now measure distinct vibrational modes at interfaces in multilayered structures, defects, and other inhomogeneities.\u00a0<\/span>\u00a0<\/span><\/p>\n

\u201cOur team combined such measurements with\u00a0laser probes and theoretical investigations to\u00a0obtain a complete picture of the\u00a0underlying physics that\u00a0ultimately will form the basis of new technologies,\u201d Pantelides said.\u00a0<\/span>\u00a0<\/span><\/p>\n

In this research, published in the journal\u00a0<\/span>Nature<\/span><\/i>\u00a0on\u00a0<\/span>Jan. 26<\/span>, the team layered two different oxides into a Lego-like nanostructure called a superlattice. The structures were imaged at the atomic scale by\u00a0<\/span>Eric Hoglund<\/span><\/a>, the paper\u2019s first author and a researcher at the University of Virginia.\u00a0<\/span>Jordan A. Hachtel<\/span><\/a>\u00a0(Ph.D.\u201916), a former student of Pantelides and an expert microscopist at the Center for Nanophase Materials Sciences at Oak Ridge National Laboratory, performed the precision measurements of vibrational modes of these complex superlattices.\u00a0<\/span>\u00a0<\/span><\/p>\n

Caldwell, Flowers Family Chancellor\u2019s Faculty Fellow in Engineering and associate professor of mechanical engineering, and his student Joseph Matson performed complementary infrared spectroscopies of the vibrational modes. Pantelides, University Distinguished Professor of Physics and Engineering, William A. and Nancy F. McMinn Professor of physics and professor of electrical engineering, and his group members Andrew O\u2019Hara and De-Liang Bao, research assistant professor and postdoctoral scholar, respectively, performed the theoretical calculations that provided links between diverse experiments to construct a comprehensive picture. The combined research established that as the thickness of the layers in the superlattices shrinks, the atomic vibrations are initially dominated by those of the two bulk materials, but gradually evolves to be dominated by the atomic interfaces, which define a new crystal structure.\u00a0<\/span>\u00a0<\/span><\/p>\n

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a) left: Schematic of the atomic positions in a 2\u00d72 superlattice (SL2); right: atomic-resolution STEM image. (Submitted image)<\/figcaption><\/figure>\n

WHY IT MATTERS<\/span>\u00a0<\/span><\/h4>\n

\u201cAny time there is a structure with new properties,\u00a0the engineering mind goes straight to thinking of what new materials with\u00a0novel\u00a0functionalities\u00a0and new devices\u00a0can be made. Simply put, this is how technology gets created<\/em>.\u201d\u00a0<\/span>\u00a0<\/span><\/p><\/blockquote>\n

Earlier combinations of theoretical\u00a0calculations using\u00a0quantum mechanics with physical experiments allowed physicists and engineers to\u00a0understand\u00a0how materials behave.\u00a0Such investigations\u00a0resulted in the creation and development of the digital devices we take for granted today.\u00a0Electron microscopes played a major role in these quests, but, until recently, they did not have sufficient resolution to image atomic vibrations.\u00a0<\/span>\u00a0<\/span><\/p>\n

\u201cEmergent properties result\u00a0at the nanoscale, especially\u00a0when we put\u00a0materials\u00a0together. From these combinations we\u00a0get new behaviors\u00a0that\u00a0we didn\u2019t expect,\u201d Pantelides said. \u201cAny time there is a structure with new properties,\u00a0the engineering mind goes straight to thinking of what new materials with\u00a0novel\u00a0functionalities\u00a0and new devices\u00a0can be made. Simply put, this is how technology gets created.\u201d\u00a0<\/span>\u00a0<\/span><\/p>\n

Caldwell and Matson have been investigating\u00a0the infrared properties of\u00a0atomic-scale superlattices. \u201cThe infrared properties of polar crystals\u00a0are\u00a0primarily driven by the optical phonons of the materials. Thus, this work builds on a concept we refer to as the crystalline hybrid, where combinations of atomically thin materials in superlattices can be used to induce emergent properties,\u201d\u00a0Caldwell said.\u00a0This effort was significantly enhanced by demonstrating that\u00a0the scale of\u00a0these\u00a0measurements can be shrunk to\u00a0measure\u00a0the most\u00a0precise behavior\u00a0captured to date.\u00a0\u00a0<\/span>\u00a0<\/span><\/p>\n

WHAT\u2019S NEXT<\/span>\u00a0<\/span><\/h4>\n

This work has the potential to improve knowledge across microscopy, optical science, physics and engineering. \u201cWe have reached a step change in this technology. By improving how we measure, we are able to better work with and manipulate these nanomaterials. We are much more confident that we can design structures with custom properties,\u201d Pantelides said.\u00a0\u00a0<\/span>\u00a0<\/span><\/p>\n

Pantelides\u00a0and Caldwell will continue collaborating with Oak Ridge National Laboratory to pursue more advances in the field, especially in expanding to different crystal structures and other material systems of interest such as nitride-based semiconductors.<\/span>\u00a0<\/span><\/p>\n

FUNDING<\/span>\u00a0<\/span><\/h4>\n

Pantelides\u2019 contributions\u00a0at Vanderbilt\u00a0were\u00a0<\/span>supported by the U.S.\u00a0Department of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering Directorate grant number DE-FG02-09ER46554 and by the McMinn Endowment.\u00a0Caldwell\u2019s contributions were supported by\u00a0the National Science Foundation\u00a0Division of Materials Research award number 1904793.\u00a0<\/span>\u00a0<\/span><\/p>\n

GO DEEPER<\/span>\u00a0<\/span><\/h4>\n

The article, \u201cEmergent interface vibrational structure of oxide superlattices<\/a>\u201d was published in the journal\u00a0<\/span>Nature<\/span><\/i>\u00a0on\u00a0<\/span>Jan. 26.<\/span>\u00a0<\/span>\u00a0<\/span><\/p>\n

Researchers<\/span>\u00a0from the University of Virginia, Sandia National Laboratory, University of California Berkeley, Purdue University,\u00a0and Humboldt University and the Paul-Drude-Institut\u00a0fur\u00a0Festk\u00f6rperelektronik\u00a0in Germany participated in this research.\u00a0<\/span>\u00a0<\/span><\/p>\n<\/div>\n

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Keep Reading<\/a><\/h3>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Vanderbilt researchers\u00a0Sokrates Pantelides\u00a0and\u00a0Joshua Caldwell\u00a0are part of an international collaboration that has demonstrated a new\u00a0way\u00a0to manipulate and measure\u00a0subtle atomic vibrations\u00a0in\u00a0nanomaterials.\u00a0This breakthrough\u00a0could make it possible\u00a0to develop customized functionalities\u00a0to improve\u00a0on and build new\u00a0technologies.\u00a0 Sokrates Pantelides\u00a0 Joshua Caldwell\u00a0 Electron beams in powerful microscopes have probed materials and nanostructures with atomic-scale resolution, imaged the atomic arrangements and, in combination with…<\/p>\n","protected":false},"author":3411,"featured_media":3563,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[84,51,12],"class_list":["post-3562","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","tag-josh-caldwell","tag-sokrates-pantelides","tag-vinse-faculty-news"],"_links":{"self":[{"href":"https:\/\/my.vanderbilt.edu\/vinsenews\/wp-json\/wp\/v2\/posts\/3562","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/my.vanderbilt.edu\/vinsenews\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/my.vanderbilt.edu\/vinsenews\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/my.vanderbilt.edu\/vinsenews\/wp-json\/wp\/v2\/users\/3411"}],"replies":[{"embeddable":true,"href":"https:\/\/my.vanderbilt.edu\/vinsenews\/wp-json\/wp\/v2\/comments?post=3562"}],"version-history":[{"count":1,"href":"https:\/\/my.vanderbilt.edu\/vinsenews\/wp-json\/wp\/v2\/posts\/3562\/revisions"}],"predecessor-version":[{"id":3564,"href":"https:\/\/my.vanderbilt.edu\/vinsenews\/wp-json\/wp\/v2\/posts\/3562\/revisions\/3564"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/my.vanderbilt.edu\/vinsenews\/wp-json\/wp\/v2\/media\/3563"}],"wp:attachment":[{"href":"https:\/\/my.vanderbilt.edu\/vinsenews\/wp-json\/wp\/v2\/media?parent=3562"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/my.vanderbilt.edu\/vinsenews\/wp-json\/wp\/v2\/categories?post=3562"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/my.vanderbilt.edu\/vinsenews\/wp-json\/wp\/v2\/tags?post=3562"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}