Stanford Synchrotron Radiation Lightsource

Structurally incorporated impurities have been shown to have systematic effects on the rate of the thermally driven transformations in titania nanoparticles. For example, the anatase-to-rutile transformation is slowed when anatase nanoparticles are doped with a cation of valence >+4, but favored when the valence < +4. Based on these observations, Y³⁺ dopants should promote the anatase-to-rutile transformation. However, prior studies showed that the transformation is actually inhibited by such impurities. So far these [1,2], observations have remained unexplained.

With the completion of the Human Genome Project and the emerging proteomics era, the biosciences community is beginning the daunting task of understanding the structures and the structure-function relations of collections of interacting proteins. Cellular activity, which is tightly regulated, often results from protein-protein and protein-nucleic acid interactions, leading to the formation of large assemblies of biomolecules for distinct functions. Examples include DNA condensation during the cell cycle, and bundle and network formation of filamentous actin proteins in cell attachment, motility, and cytokinesis.

A team of scientists, working in part at SSRL's crystallography beam lines and led by Stanford Professor Roger Kornberg, has determined for the first time the atomic structure (at 1.1 Å resolution) of a thiol-covered gold nanoparticle, a discovery with potential for a range of applications from biosensors to nanotransistors. The results are published in the October 19 issue of Science.

New approaches to the fabrication of ferroelectric nanostructures onto substrates are critical for the development of competitive functional devices that successfully integrate at nanoscale ferroelectrics as alternative materials in the microelectronic industry. These approaches have to meet reliability and utilization requirements to realize a cost-effective production of an increasing demand for ultra-high-density memories or nanometric electromechanical systems. An important challenge in the fabrication of ferroelectric nanomaterials supported onto substrates is the ability to fabricate an organized arrangement of the nanostructures. This is a key point for the applications of ferroelectrics in nanoelectronic devices.

Crystals of different sizes and shapes have different functional properties. This is certainly true in the case of platinum nanocrystals, which can be used to increase catalytic reactions including hydrogen cell fuel oxidation. Understanding crystallization processes will allow researchers to fine-tune the shape, size, and quality of crystals for specific, tailored applications.

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.

X-ray microscopy is a useful tool for visualizing functional materials on the nanoscale.  X-ray holography replaces the lens with a computer and obtains an image by Fourier inversion of the interference pattern. While in principle the resolution limit is given by the x-ray wavelength, in practice, the resolution is limited by the size of the reference being used.

To expand the use of hydrogen in mobile applications—such as hydrogen-powered buses and cars—researchers will need to design lightweight, compact means of storing it. One possible method is to store hydrogen inside carbon nanotubes. Theoretical predictions suggest that, through a mechanism that forms stable carbon-hydrogen bonds, it would be possible to store one hydrogen atom for every carbon atom inside single-walled carbon nanotubes.

As an important step toward reducing oil dependence and greenhouse gas production, electric vehicles are becoming more and more prevalent. However, one major barrier remains: their batteries. Today’s lithium-ion technology has yet to meet energy density, cost, life cycle and safety goals.

In the well-known Greek legend the touch of King Midas would convert anything to metallic gold. Recently, a team working at SSRL lead by Professor Jorge Gardea-Torresdey from the University of Texas at El Paso have shown that ordinary alfalfa plants can accumulate very small particles (nanoparticles) of metallic gold (1). The best-known materials that contain nanoparticles of metallic gold are gold colloids. These lack the familiar metallic luster, but show bright colors which range from red, violet or blue, depending upon the size of the nanoparticles (2,3).