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.
Cooperative Growth of Large Single-Crystal Graphene Islands
June 12, 2014 — Researchers showed that it is possible to grow large, single-crystal graphene islands by controlling the nucleation density, which determines the growth mechanism.
Polar ordering induced by oxygen vacancies
June 02, 2014 — A combination of scanning transmission electron microscopy (STEM), electron energy loss spectroscopy (EELS) and density functional theory (DFT) calculations show that it is possible to achieve polar order in a superlattice made up of two non-polar oxides by means of oxygen vacancy ordering.
Stable Nanopores in Graphene
June 02, 2014 — The existence of stable holes in graphene has been demonstrated. This is a major step toward the development of robust and reliable graphene-based nanopore devices that could be used, for example, in DNA sequencing.
Clues for absence of superconductivity in an iron-based material
May 27, 2014 — The electronic properties of CaFe2As2, using a combination of bulk transport measurements and surface photoemission spectroscopy, have revealed reasons for the lack of superconductivity. These results support the suggested role of magnetism and spin fluctuations in iron-based superconductors.
Versatile Approach to Polymeric Molecular Sieve Membranes with Hierarchical and Tailorable Porosity
May 19, 2014 — Scientific Achievement: A facile, versatile one-pot approach for the preparation of hierarchically macro-, meso- and microporous polymeric molecular sieve membranes via in situ cross-linking has been developed
Thiolate Ligands as a Double-Edged Sword for Catalysis by Thilated Gold Nanoclusters
May 19, 2014 — Scientific Achievement: Thiolate ligands in gold cluster compounds are revealed to be a ‘double-edged sword’: ligands protect and stabilize the cluster but block sites responsible for catalytic activity.
Atom Substitution Gives Stable Performance of Solid Electrolytes
May 07, 2014 — The substitution of Ge for As in Li3AsS4 results in an exceptionally stable ionic conductivity versus temperature, and enhances the ionic conductivity by two orders of magnitude. The performance of solid state batteries is dramatically sensitive to temperature due to the energy barrier associated with Li ion motion.
Origin of anomalous atomic vibrations in efficient thermoelectrics revealed
May 06, 2014 — Thermoelectric SnTe and PbTe compounds were investigated with inelastic neutron scattering (INS) and first-principles calculations to understand the basis of their anharmonic lattice dynamics. The phonon anharmonicity of these materials is of both fundamental importance and of practical interest.
A Bi-Functional Electrolyte Design for Long Lasting Batteries
April 24, 2014 — An innovative design of a bi-functional electrolyte defies the theoretical maximum energy capacity of conventional lithium carbon fluoride (Li-CFx) batteries. This novel design has the potential of enabling the creation of long lasting batteries for implantable medical devices, wearable electronics and other applications.