Phonon localization drives nanoregions in a relaxor ferroelectric
April 11, 2014 — Neutron scattering measurements reveal that phonon localization drives the generation of polar nanoregions (PNRs) in a relaxor ferroelectric. PNRs facilitate the ability of relaxor ferroelectrics to convert between electrical and mechanical forms of energy, which is used in applications ranging from medical ultrasound to military sonar devices.
New imaging-based chemical analysis of atomic layers
February 14, 2014 — A new Z-contrast image analysis method now allows dopant atoms in two-dimensional materials to be located and quantified. With this ability, the distribution of dopants can be verified as the physical and chemical properties are modified. This new capability was used to study doped molybdenum disulfide in which the optical band gap was tuned between 1.85 and 1.
Glass-like thermal transport in AgSbTe2: nano-scale insights to improve thermoelectric efficiency
May 16, 2013 — A spontaneously forming nanostructure is identified as the origin of the extremely low glass-like thermal conductivity of AgSbTe2.
Graphitic layers suppress the coarsening of single-atom catalyst
May 10, 2013 — Niobium atoms can be stabilized in graphitic layers, and the resulting carbide complex exhibits higher catalytic activity compared to commercial platinum nanoclusters. This stabilization of single atoms overcomes the known problems of coarsening and cost encountered with the alternate approach of noble-metal sub-nanoclusters, which also exhibit excellent catalytic activities.
Neutrons reveal key role of water in polyelectrolyte dynamics
March 26, 2013 — Combined neutron scattering and computational results show that the charge on a water-dissolved polymer accelerates its dynamics through an increase in the amount of water contained within the molecule. Such polyelectrolytes, i.e.
New nanostructured phosphors for photonics and white LEDs
March 12, 2013 — A new family of one-dimensional nanostructures based on novel crystal structures has been discovered that produces strong, tunable, visible-light luminescence.
Combining diffraction theory with electronic-structure theory of solids to decode electron-energy-loss spectra
January 18, 2013 — A theory combining both a material’s electronic structure and electron beam propagation has been developed at Vanderbilt University in conjunction with experimental data obtained at Oak Ridge National Laboratory.
Sub-nanometer electron probes map magnetism at the nanoscale
December 05, 2012 — For the first time, the electron microscope has been used to map the magnetization of nanoparticles in real space with sub-nanometer spatial resolution, along with their structure, chemistry and electronic properties. Research on magnetic materials has long been hampered by the lack of real-space probes capable of looking at these systems with true sub-nanometer resolution.