Using neutrons to probe and understand battery interfaces
February 14, 2014 — Neutron reflectometry at the Spallation Neutron Source has revealed the composition and growth characteristics of the spontaneous chemical reaction layer formed between a silicon battery anode and an organic electrolyte that ultimately limits the capacity of the battery. We determined that a 3.
Anomalous Photodeposition of Ag on Ferroelectric Surfaces with Below Bandgap Excitation
February 14, 2014 — Photochemical deposition of elemental Ag nanoparticles on a ferroelectric substrate with sub bandgap transmitted white light indicates light confinement and non-linear optical phenomena. This innovation opens the pathway to unprecedented fine control and optimization of the growth of functional nanostructures for potential applications ranging from chemical sensing to high speed data transfer.
Evidence for non-uniform superconductivity in iron-based materials
January 31, 2014 — Multi-scale bulk and local electronic and structural studies on an iron-based superconductor have revealed, for the first time, an origin of non-bulk superconductivity. Understanding the role of chemical doping in causing superconductivity can potentially lead to the design of advanced high-temperature superconductors (HTS).
Air-Stable, High-Conduction Solid Electrolytes for Electrical Energy Storage
January 24, 2014 — A substituted Li4SnS4 solid electrolyte has been designed and demonstrated to have excellent air stability and exceptionally high ionic conductivity. This discovery opens the possibility for the design of new batteries that are safer and have higher energy density than today’s batteries.
Enhancing Tunneling Electroresistance by Interfacial Phase Transitions
January 22, 2014 — The tunneling electroresistance (TER) in ultrathin ferroelectric tunnel junctions (FTJs) is found to be critically dependent upon interface state phase transitions induced by the ferroelectric (FE) polarization.
Structure and Composition of Nanometer-Sized Nitrides in a Creep-Resistant Cast Austenitic Alloy
December 20, 2013 — The microstructure of a new and improved high-temperature creep-resistant cast austenitic alloy, CF8C-Plus, was characterized after creep-rupture testing at 1023 K (750ºC) and 100 MPa. Microstructures were investigated by detailed scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy (EDS).
Orienting oxygen defects for enhanced oxygen reduction kinetics
November 20, 2013 — Functional oxygen defects are shown to result in a two orders of magnitude improvement of the catalytic oxygen reduction kinetics in epitaxial SrCoO2.5 films. This discovery will impact our understanding of the fundamental properties in multivalent transition metal oxides and provides technological insights into developing new strategies for advanced energy materials and systems.
Local structures ‒ key to improved gas adsorption in carbon materials
September 23, 2013 — Combined results from electron microscopy, neutron scattering, and theory, illustrate the link between local structures and adsorption properties in carbon materials.
Epitaxial oxygen sponges as low temperature catalysts
September 10, 2013 — Fast and reversible redox reactions at considerably reduced temperatures are achieved by epitaxial stabilization of multivalent transition metal oxides. This illustrates the unprecedented potential of complex oxides for oxide-ionics, where oxidation state changes are used for energy generation, storage and electrochemical sensing.
Fluid-like electrophoretic behavior observed in a solid crystal
September 03, 2013 — The position of coexisting mesoscale electronic phase domains in a complex oxide is shown to be controlled with electric fields in an electrophoretic process previously only observed in liquids. This discovery has important implications to our fundamental understanding of how electronic phase competition arises and persists while opening the door to new types of resistive switching possibilities.