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Science & Research Highlights 2004

Structure of new DNA enzyme family member found

NOVEMBER 5, 2004

Cornell University researchers, who are trying to understand how proteins evolve and function by looking at their structural features, used the APS and the Cornell High Energy Synchrotron Source to uncover the crystal structure of a protein involved in making the building blocks of DNA correctly.
Experimental data from sector 1

New method studies living bacteria cells

OCTOBER 29, 2004

Researchers at the U.S. Department of Energy's Argonne National Laboratory have found a new way to study individual living bacteria cells and analyze their chemistry. (Image © 2004 American Chemical Society)

Superstructures add to superconducting mystery

OCTOBER 15, 2004

The discovery of oxygen "superstructures" in cuprate materials by two independent teams of physicists could help shed new light on the origins of high-temperature superconductivity, which has been one of the biggest mysteries in physics for almost 20 years. The results, which back up theoretical predictions made almost 15 years ago, suggest that the "stripes" of charge found in some high-temperature superconductors might not be as closely related to the ability of these materials to carry currents without resistance as was previously thought.
Characterization of 2D nanocrystal superlattices formed by colloidal droplet evaporation.

Dynamical Self-Assembly of Nanocrystal Superlattices during Colloidal Droplet Evaporation by in situ Small Angle X-Ray Scattering

OCTOBER 11, 2004

The nucleation and growth kinetics of highly ordered gold nanocrystal superlattices during the evaporation of nanocrystal colloidal droplets was elucidated by in situ time-resolved small-angle x-ray scattering experiments carried out at sector 1 of the APS. (Image ©2004 The American Physical Society)
X-ray scattering pattern from ferroelectric stripe domains in a thin film of lead titanate three unit cells thick.

Visualizing an unusual geometry shift

SEPTEMBER 21, 2004

A paper by Philip Coppens et al. in the Royal Society of Chemistry (RSC) Journal Chemical Communications is featured on the "RSC Hot Papers Web Page." 
X-ray scattering pattern from ferroelectric stripe domains in a thin film of lead titanate three unit cells thick.

Are Films Ferroelectric?

JUNE 25, 2004

Thin films of ferroelectric material for use in future "electronic" devices can be as thin as developers desire without loss of function according to a synchrotron x-ray study carried out by researchers using the BESSRC/XOR beamline 12-ID at the APS. The results show that a thin film of one particular ferroelectric material, lead titanate, is still stable even in a layer a mere 1.2 nanometers thin, three unit cell layers thick.
Levitated liquid-aluminum-oxide sample in a super-cooled state at ~1800 C. The sample is levitated by an oxygen gas stream and heated by a 270-W CO2 laser. The article reports on inelastic x-ray measurements performed on this sample.

X-rayed Movie

JUNE 11, 2004

A research team using the Cornell High Energy Synchrotron Source and the Complex Materials Consortium sector 9 beamline at the Advanced Photon Source has produced the fastest movies ever made of electron motion. Created by scattering x rays off of water, the movies show electrons sloshing in water molecules, and each frame lasts just 4 attoseconds (quintillionths of a second). The results, published in the 11 June PRL, could let researchers "watch" chemical reactions even faster than those viewable with today's "ultrafast" pulsed lasers.
Levitated liquid-aluminum-oxide sample in a super-cooled state at ~1800 C. The sample is levitated by an oxygen gas stream and heated by a 270-W CO2 laser. The article reports on inelastic x-ray measurements performed on this sample.

New X-ray Tool Reveals Details of Ferroelectric Switching

JUNE 9, 2004

All of our current information technology relies on devices that process information as binary ones and zeroes. Ferroelectric materials are of special interest to developers of the next generation of such devices because they exhibit polarized electronic states that can represent bits of information. Moreover, these materials retain their polarization states without consuming electrical power, making ferroelectrics the subject of intense study for nonvolatile memory applications in which data is stored even when the power is turned off. One problem, however, is polarization fatigue; after a number of cycles, the switchable polarization begins to taper off, rendering the device unusable. Recently, a team of researchers from the University of Wisconsin, Bell Laboratories, and the University of Michigan used the x-ray synchrotron at the Advanced Photon Source (APS) to study the micron-scale details of polarization fatigue in ferroelectric oxides.