Easy phase transitions spur high piezoelectric responses
July 14, 2015 — Theoretical calculations, based on newly obtained experimental geometries in strained BiFeO3 thin films, predict an almost barrierless transition between co-existing phases. This facile transition provides insight into the origin of the high electromechanical responses found in coexisting phases in this Pb-free material.
New model predicts formation of stable high-entropy alloys
April 09, 2015 — Researchers devised a model that can predict which combinations of 5 or more elements will form new “high-entropy alloys.” This work, which utilizes values obtained from data mining of high-throughput calculations of binary compounds, requires no experimental or empirically derived input and advances capabilities for “materials by design.
Scientists Connect Thermoelectric Materials and Topological Insulators
January 20, 2015 — Quantum mechanical calculations of electronic structure and transport for Bi2Te3 and its sister material Bi2Te2Se solved the long-standing puzzle of why many materials that are topological insulators are also excellent thermoelectrics.
Facets and disorder hold key to battery materials performance
December 10, 2014 — A synergistic combination of atomic-scale experiment and theory identify Ni antisites as the predominant defects in a lithium–manganese-rich cathode material. In addition, their formation energies are facet-dependent, with larger defect concentrations observed at open (010) facets.
Strain-induced vacancy stability shown across an interface
November 12, 2014 — Density functional theory (DFT) calculations show that among the four types of (001) SrTiO3 | (001) MgO interface structures, the TiO2-terminated SrTiO3 containing electrostatically attractive Mg–O and Ti–O ion–ion interactions form the most stable interface.
Shaking the bonds: Atomic vibrations drive insulator to metal
November 10, 2014 — Neutron and x-ray experiments, coupled with large-scale first-principles calculations have revealed the origin of the metal–insulator transition in vanadium dioxide, an intractable question in phase stability for more than 50 years.
Predictive calculations of cuprate magnetic properties
June 24, 2014 — Magnetic couplings in a realistic cuprate system have been correctly predicted for the first time with highly accurate Quantum Monte Carlo (QMC) calculations. Effective magnetic models of superconductivity (previously reliant on experiment) can now be derived with confidence from theory, which could lead to better fundamental predictions of superconductor behavior.
Elementary excitations in liquids
May 15, 2013 — Elementary excitations in metallic liquids were discovered through computer simulation, representing a major advance in the physics of liquids. In solids the elementary excitations of lattice dynamics are phonons, but in liquids they have a very short lifetime.