April 2014
Feng Lin, Lawrence Berkeley National Laboratory , Marca Doeff, Lawrence Berkeley National Laboratory, Dennis Nordlund, Stanford Synchrotron Radiation Lightsource, Tsu-Chien Weng, Stanford Synchrotron Radiation Lightsource
Rechargeable lithium-ion batteries are widely used in applications ranging from consumer electronics to electric vehicles. An important feature of a high-quality battery is a long lifetime, i.e. a large number of possible charge-discharge cycles. However, every cycle introduces changes in the battery’s electrode material, limiting its cyclability. A research collaboration has recently examined the occurring structural and chemical changes in the electrode material during cycling and linked them to the performance of lithium-ion batteries.
X-ray Absorption Spectroscopy
BL10-1
April 2014
Donghui Lu, Stanford Synchrotron Radiation Lightsource
High-temperature superconductors are materials whose electrical resistance vanishes below critical temperatures that are much higher than for conventional superconductors. As potential energy-saving electrical conductor materials, they are of immense interest for a wide range of industrial applications. Despite extensive research, the exact mechanism behind high-temperature superconductivity has remained an unsolved mystery. Now, an international team of researchers has solved an important piece of the puzzle. Read more...
Angle-resolved photoelectron spectroscopy
BL5-4
March 2014
Fatty acids are key components of a variety of biological functions ranging from cellular membranes to energy storage. In addition, they are of great interest as potential “green” biofuels and targets in the development of novel antibiotics. In order to fully exploit their potential, researchers must first understand in detail how organisms synthesize fatty acids. However, due to the dynamic nature of the process, structural and functional studies of fatty acid biosynthesis are very challenging. A team of scientists has recently made a giant leap forward by determining the structure of a protein–protein complex that represents a snapshot of fatty acid biosynthesis in action.
Macromolecular Crystallography
BL12-2
March 2014
Proteins are molecules with a wide range of functions in all living organisms. As potential drug targets, they are of great interest for pharmaceutical and medical research. Proteins are built from long amino acid chains that fold up into three-dimensional structures, which determine the proteins’ functions. In most cases, proteins fold into only one specific, albeit, dynamic structure. Now, scientists have determined that the protein VP40 of the Ebola virus assumes three completely different structures with three very different biological functions.
Macromolecular Crystallography
BL11-1, BL12-2
February 2014
Yijin Liu, SSRL, Wenge Yang, Carnegie Institution of Washington / Center of High Pressure Science and Technology Advanced Research (China)
It is common knowledge that materials expand when heated. However, a chemical compound known as BiNiO3 proves to be quite extraordinary in that it contracts with rising temperature. By mixing BiNiO3 with “conventionally” expanding materials, it becomes possible to produce composite materials with zero or other desired thermal expansion values – a possibility with great potential for engineering and other applications. The same transition from a low-density to a high-density phase of BiNiO3 observed for increasing temperatures can also be induced by applying high pressure.
BL6-2, BL6-2c
February 2014
Samaresh Guchhait, University of Texas at Austin, Hendrik Ohldag, SSRL
Carbon-based materials are extremely lightweight and have thermal, mechanical and electrical properties that are of great interest for use in functional devices. Carbon materials can be manufactured in virtually any shape and even with dimensions on the micro- and nanoscales. Recent research is now aimed at exploiting the spin and magnetism of carbon-based materials for data storage devices – a field called spintronics.
X-ray diffraction
BL11-3, BL13-1
February 2014
Sarp Kaya, SUNCAT, Frank Abild-Pedersen, SUNCAT
Graphite and diamond are two distinct forms of the same element, carbon. Nevertheless, their properties could not be any more different. For instance, diamond is extremely hard and can be used in cutting tools. Graphite, on the other hand, is soft and used in pencils. Graphite can be converted into diamond in a process that usually requires very high pressure. However, scientists have recently suggested an alternative route to obtain diamond-like structures from graphite – at least on the nanoscale.
X-ray Absorption Spectroscopy, Photoemission spectroscopy
BL13-2
January 2014
Yulin Chen, Stanford University, Oxford University, Zhi-Xun Shen, Stanford University
Topological insulators comprise a new state of quantum matter that has been predicted theoretically and realized experimentally in the past few years. Strong inversion asymmetry in topological insulators could lead to many interesting phenomena, such as pyroelectricity, intrinsic topological p-n junctions and topological magneto-electric effects.
Researchers using Beam Line 5-4 at SSRL and Beam Line 10.0.1 at the ALS have shown the compound BiTeCl to be the first topological insulator with a strong inversion asymmetric crystal structure.
Angle-resolved photoelectron spectroscopy
BL5-4
December 2013
Hirohito Ogaswara, SSRL
Polymer-electrolyte-membrane (PEM) fuel cells are potential candidates for the environmentally friendly and cost-efficient production of renewable energy from hydrogen and oxygen. At the fuel cell’s anode, hydrogen gas is split into protons, which subsequently combine with oxygen gas at the cathode to produce water. However, current PEM fuel cells are limited in their efficiency by the occurrence of several competing oxygenated intermediates at the cathode. A research team has now shed light on the interplay between different oxygenated species and fuel-cell performance.
BL13-2
November 2013
Wendy Mao, Stanford University
Earth’s inner structure is organized into layers. The outermost crust overlays the mantle, which, in turn, surrounds our planet’s core. The crust and mantle are mainly composed of silicate rocks. In contrast, Earth’s core is metallic, containing predominantly iron. But how did iron separate from the silicates in order to form the metallic core during Earth’s evolution? Researchers have recently provided evidence that the percolation of liquid iron alloys through a solid silicate matrix can explain the formation of Earth’s core.
BL6-2
