Anomaly in Materials

Anomaly in materials refers to an abnormal behavior of a property with respect to external fields such as temperature, pressure, and electric and magnetic fields. Typical examples of anomaly are phase transformations in which either first or second derivatives of free energy with respect to external fields are discontinuous due to different properties of different phases. However, anomaly in a macroscopically homogeneous phase is less understood. Recently, based on fundamental thermodynamics we have demonstrated that anomaly in a single phase originates from the limit of stability of the phase and can be predicted through first-principles calculations, CALPHAD modeling, and statistic mechanics. As a specific example, we show quantitatively that thermal expansion can be normally positive, colossally positive, zero, negative, or infinitely negative. This capability provides new routes for design of materials with extraordinary performances.

Biography

Dr. Zi-Kui Liu is a professor of Materials Science and Engineering at The Pennsylvania State University (http://www.matse.psu.edu/faculty/liu). He obtained his BS from Central South University (China), MS from University of Science and Technology Beijing (China), PhD from Royal Institute of Technology (KTH, Sweden). He was a research associate at University of Wisconsin-Madison and a senior research scientist at Questek Innovation, LLC. He has been at the Pennsylvania State University since 1999, the Editor-in-Chief of CALPHAD journal since 2001, and the President of CALPHAD, Inc. since 2013. Dr. Liu is a Fellow and a member of Board of Trustees of ASM International and was as a member of the TMS Board of Directors. He received the TMS Brimacombe Medalist Award, the ACers Spriggs Phase Equilibria Award, the ASM J. Willard Gibbs Phase Equilibria Award, and the Wilson Award for Excellence in Research from the Pennsylvania State University.

Dr. Liu’s current research activities are centered on first-principles calculations, modeling of thermodynamic and kinetic properties, and their integration in understanding defects, phase stability, and phase transformations, and designing and tailoring materials processing and properties. He is the founder and the director of Center for Computational Materials Design, has published over 360 papers in peer-reviewed journals (www.researcherid.com/rid/A-8196-2009), and has graduated 21 B.S., 8 M.S., and 21 Ph.D. students. His group web site is at www.phases.psu.edu.