image: A higher magnification of the image shows more clearly how the atoms are arranged on both sides of the twin boundary, which is represented with a line of yellow atoms in the center of the image. view more
Credit: Martin Harmer and Christopher Marvel, Lehigh University
The W.M. Keck Foundation has awarded a $1 million grant to Lehigh University to study and discover the mechanisms that govern anti-thermal processes that appear to reverse nature. The work has the potential to revolutionize scientists' basic understanding of thermal processes and inform the development of new materials that could withstand higher temperatures. A breakthrough in this area could lead to significant increases in engine efficiency, for example, saving billions of dollars in fuel costs.
Known for funding science and engineering projects with the potential to pioneer new territory in a field, the Keck Foundation has awarded the grant to principal investigator, Martin Harmer, Alcoa Foundation Professor of Materials Science and Engineering and Senior Faculty Adviser for Engineering Research Initiatives for his project titled Anti-thermal Behavior of Materials: Reversing the Trend of Nature. Harmer's collaborators are Professor Elizabeth Holm and Professor Gregory S. Rohrer, both professors of materials science and engineering at Carnegie Mellon University.
"As Lehigh commits itself to further excelling as a research university, this Keck Foundation grant affirms the groundbreaking work and collaboration being done by our world-class faculty. This is very exciting news, and I thank the Keck Foundation for its continued support of pioneering research and discovery. Congratulations to Professor Harmer and his colleagues as they embark on this fascinating research challenge. I know they will make the most of this opportunity," said Lehigh President John D. Simon.
Added Patrick V. Farrell, Provost and Vice President for Academic Affairs at Lehigh: "The Keck Foundation proposal process is extremely competitive as the research they fund must be both very innovative and potentially very high impact. It's an outstanding opportunity for this team to explore what might seem like a material anomaly in order to understand the underlying mechanism and perhaps extend existing examples to new materials and new applications. I look forward to seeing their results and what impact those results might have in practical applications."
Reversing the trend of nature
The team will be working to understand a phenomenon about which very little is currently known: atoms that behave in a manner contrary to nature.
The atoms in solids typically move exponentially faster with increasing temperature, obeying a classical law of physics. This motion fundamentally limits the properties and performance of materials. For example, turbine engine components start to weaken at higher temperatures limiting the maximum operating temperature and efficiency of the engine.
A grand challenge in condensed matter science is to combat this trend of nature in order to produce materials that are more efficient, resilient and enduring. Researchers at Lehigh University, Carnegie Mellon University and Karlsruhe Institute of Technology have recently identified examples of several processes which actually become slower, or do not change at all, as the temperature increases. These are referred to as anti-thermal. Anti-thermal behavior has been detected in isolated cases in metals, ceramics, semiconductors, polymers and biomaterials.
In experimental and atomistic simulation studies of nanograin metals, grains -- microscopic crystals that form the metal -- were found to grow exponentially faster than expected at room temperature. In another experimental study--a collaboration that included investigators at Lehigh, Karlsruhe Institute of Technology, and Aveiro University -- the grains in a ceramic grew more slowly at higher temperatures--the very opposite of expected behavior.
The researchers' goal is to study and discover the unknown atomic mechanisms that govern this intriguing type of anti-thermal behavior. They will then use this understanding to design new materials with enhanced thermal performance that have the ability, for example, to increase the operating temperature and efficiency of engines, or the service life of bulk nanograin solids.
"I'm extremely grateful to the W.M. Keck Foundation for their vision in supporting and enabling high risk research, such as this," said principal investigator Martin Harmer. "This project will allow us to explore unchartered territory that could potentially uncover the secrets of nature's counter intuitive thermal behavior and pioneer new approaches to materials science. My graduate student, Chris Marvel refers to anti-thermal behavior as the Benjamin Button phenomenon of materials science, where nature reverses its course - I like his analogy!"
Leveraging world-class microscopy instruments
Prior to the anti-thermal project, Harmer and his collaborators pioneered a concept known as grain boundary complexions, which treats grain boundaries as distinct states-of-matter in thermodynamic equilibrium. At Lehigh, Harmer and his students use a world-class electron microscopy facility for analyzing and imaging atoms at these grain boundaries.
With W.M. Keck funding, Professor Harmer and his colleagues will apply a novel method for measuring grain boundary motion inside multigrain materials. The team will seek to understand the process by applying methods of atomistic computer simulation and utilizing Lehigh's atomic resolution electron microscopy instruments to directly image the atom movements associated with anti-thermal behavior. An imaging stage will be utilized to make in-situ observations of atom movements at operating temperatures.
"This innovative and bold project holds great potential to completely transform the way that we approach the development of materials for high-end thermally challenging applications," said John Coulter, interim dean of Lehigh University's P.C. Rossin College of Engineering and Applied Science. "We are very appreciative of the support of the Keck Foundation, and proud of the Lehigh-Carnegie Mellon team that won this honor."
A dream team
Another core strength of the project is the team's long history of productive and synergistic collaboration. To integrate all research into a cohesive hypothesis-driven theoretical and experimental endeavor, Professor Harmer will apply his expertise in grain boundary complexions and atomic resolution electron microscopy; Professor Holm her expertise in computational simulation of atom movements in grain boundaries; and, Professor Rohrer his knowledge of 3D microstructural networks to measure grain boundary mobility.
Earlier this year, Professor Harmer was named a Distinguished Life Member of the American Ceramic Society (ACerS), the highest honor accorded members of this scientific and technical organization and its most prestigious level of membership. It is awarded in recognition of a member's contribution to the ceramics profession.
Over the course of more than two decades as director of Lehigh's Center for Advanced Materials and Nanotechnology, Professor Harmer helped develop it into one of the most highly respected materials research centers in the U.S. His research has focused on advancing the fundamental understanding of microstructure control, sintering, grain growth and transport behavior of ceramics and metals, for tailoring material properties and performance.
The Los Angeles-based W. M. Keck Foundation was established in 1954 by the late W. M. Keck, founder of Superior Oil Co. The foundation focuses its support on pioneering discoveries in science and engineering, medical research and undergraduate education.
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