Electrocatalysis is the science of modifying the overall rates of electrochemical reactions so that selectivity, yield and efficiency are maximized. Studies in electrocatalysis have resulted in tools such as highly selective multicomponent gas mixture sensors and better electrocatalysts for the fuel cells. Markovic and Lucas have been very active in studying the mechanisms by which these catalysts operate and developing in-situ surface x-ray scattering (SXS) techniques for their studies.
Using SSRL's beam line 5-4, researchers from Fudan University in Shanghai and SSRL have worked out the mechanism behind the formation of charge density waves in 2H-structured transition metal dichalcogenides (2H-TMD's). The results were published in the November 21, 2007 edition of Physical Review Letters.
Panoramic images are captivating in any form, with their wide field of view and extremely high resolution. Now, SSRL scientists have demonstrated a new x-ray holographic technique for imaging wide areas of a nanoscale sample without losing resolution. The results were published in the November 2007 edition of the journal Optics Letters.
A team of researchers working at SSRL Beam Line 13-3 have devised an imaging technique that combines methods from traditional x-ray crystallography and x-ray holography, circumventing one of the major technical hurdles associated with capturing detailed images of non-periodic structures. The results were published in the August 15 edition of Physical Review Letters.
The recent discovery of superconductivity in iron-based layered compounds known as iron oxypnictides has renewed interest in high-temperature superconductivity. Now, SLAC and Stanford researchers, using SSRL's angle resolved photoemission spectrometer at Beam Line 5-4, have furthered the quest to understand this iron-based compound. In a recent paper published in Nature, SSRL scientist Donghui Lu, with colleagues at SSRL and Stanford, reported on the mechanism behind the superconductivity of a lanthanum-oxygen-iron-phosphorus (LaOFeP) compound, one of the new iron-based superconducting materials.
One of the strangest consequences of quantum mechanics is the seemingly instantaneous communication of subatomic particles over long distances. Known as quantum entanglement, pairs or groups of particles can become linked so that any changes made to one will cause the others to respond quicker than the time it takes for light to travel between them.
However, the superconducting gap distributions in iron-based superconductors do not fall neatly into either of these two symmetries. Nodeless gap distributions, such as are associated with s-wave pairing symmetry have been directly observed in some members of the iron-based family of high-temperature superconductors, and the signatures of nodal superconducting gaps have been reported in others.
Solar panels contain a number of solar cells that convert light into electricity. Solar cells are traditionally made of crystalline silicon, which presently have 15-20% efficiency in conversion of light into electricity. However, these traditional cells are bulky and have high production costs that can take 5-7 years of solar panel operation to recover. Using solar cells made from organic materials could lower their production costs. This would lessen the time it takes for solar panels to generate more energy than consumed during production and would also result in more widespread application of solar energy.
Nothing seems to move as fast as the field of consumer electronics. A browse through a technology store reveals the dizzying array of space-age -seeming products like flat screen TVs, touch screen phones, and mp3 players. A new development in electronics is on the horizon, one that may bring us roll-up flat screens and high-definition display clothing. These will be made possible using the thin and energy efficient organic light emitting diodes (OLEDs), which are based on organic semiconductor technology. Both a desire for less expensive, more convenient technologies and a concern for energy conservation have heightened interest in the field of organic semiconductors.
Anthropologists learn about ancient cultures through the objects left behind. Ritualistic artifacts give glimpses into the religious and belief systems of nonextant societies. Application of new techniques of chemical and structural analysis to the study of ancient objects can give more insight into how they were made and used.
