Research Highlights

Elementary excitations in liquids

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.  The current work shows...

Scientists Connect Thermoelectric Materials and Topological Insulators

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

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....

New model predicts formation of stable high-entropy alloys

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...

Strain-induced vacancy stability shown across an interface

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 MgO and TiO ion...

Predictive calculations of cuprate magnetic properties

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...

Shaking the bonds: Atomic vibrations drive insulator to metal

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. When heated to just above room temperature, the...

Easy phase transitions spur high piezoelectric responses

Theoretical calculations, based on newly obtained experimental geometries in strained BiFeO3 thin films, predict an almost barrierless Electronic structure theory demonstrates that no barrier exists along the path between co-existing phases in compressively...

Giant Spin-Driven Electric Polarization is Revealed in Promising Multiferroic

Multiferroic materials are important because their electrical and magnetic properties are coupled.  Because BiFeO3 magnetically Comparison between the predicted and observed spin-driven polarization (above) and of the octahedral rotation angle AFD (below) are...

Quantum critical behavior in a concentrated solid solution: a new twist on structural alloys

Concentrated transition metal alloys with the formula NiCoCrx, with x≈1, and a simple cubic crystal structure, display transport, magnetic and thermodynamic signatures exhibited by more structurally complex compounds near a quantum critical point (QCP). These alloys provide...