As of September 30, 2008

for international journal X-Ray Spectrometry (John Wiley & Sons Ltd.)

Tracking the structural dynamics of human hemoglobin with nsec time resolution (September 21, 2008)

Professor A. Cupane (University of Palermo, Italy) and his colleagues at the European Synchrotron Radiation Facility (ESRF) recently established a method for structural dynamics.  The technique uses wide-angle X-ray scattering and images proteins in their natural, fast-moving state.  The research group succeeded in capturing the tertiary and quaternary conformational changes of human hemoglobin in close to physiological conditions triggered by laser-induced ligand photolysis.  The time resolution of the observation is in the order of nsec.  The whole process lasts 3 μsec, and the molecule changes from a “relaxed” form that can bond to oxygen, to a "tense" form that squeezes out the oxygen.  They also reported data on optically induced tertiary relaxations of myoglobin and refolding of cytochrome c.  For more information, see the paper, "Tracking the structural dynamics of proteins in solution using time-resolved wide-angle X-ray scattering”, M. Cammarata et al., Nature Methods, published online, 21 September 2008, doi:10.1038/nmeth.1255 

X-ray detection of shape changes of catalytic nanoparticles (September 19, 2008)

It is well known that nanoparticles often enhance catalytic activity.  However, it is still an open question as to whether the metallic or the oxidized state of the particle is the catalytically more active phase.  It is therefore significant to study the oxidation/reduction process of metallic nanoparticles. A group led by Professor H. Dosh (Max-Planck-Institut für Metallforschung, Germany) recently reported on some very interesting XRD and GISAXS studies on the oxygen-induced shape transformation of Rh nanoparticles.  The experiments were done in-situ, during the oxidation/reduction cycle at high temperature.  The group found that shape transformation is driven by the formation of a surface oxide O-Rh-O trilayer, which can stabilize Rh nanoparticles with low-index facets.  For more information, see the paper, "Shape Changes of Supported Rh Nanoparticles During Oxidation and Reduction Cycles", P. Nolte et al., Science, 321, 1654-1658 (2008). 

The highest spatial resolution in hard X-ray microscopy – 5nm – has been achieved with 100 nm beam size (August 29, 2008)

X-ray microscopy is continuing to make significant progress in two directions, through the use of advanced X-ray optical elements and through the combined use of coherent X-rays and image analysis.  Currently, the typical spatial resolution available at major synchrotron radiation facilities is the order of tens of nm.  Professor C. Schroer (Technische Universität Dresden, Germany) and his colleagues recently achieved the world record for spatial resolution in X-ray microscopy.  The research group employed the coherent x-ray diffraction imaging technique and observed a single gold nanoparticle (size <100 nm) supported by a Si₃N₄ membrane with 15.25 keV photons, beam dimensions 100×100 nm², and flux of more than 1E+8 counts/sec.  The real-space gold image was reconstructed by the hybrid input-output (HIO) method together with the shrink-wrap algorithm.  The resolution of 5 nm was achieved in 600 s exposure time.  The present experiments were done at beamline ID13, ESRF, and a pair of refractive lenses was used to increase the coherent dose density.  For more information, see the paper, "Coherent X-Ray Diffraction Imaging with Nanofocused Illumination", C. G. Schroer et al., Phys. Rev. Lett., 101, 090801 (2008).

Structure of SAM on Au(111) (August 15, 2008)

Some of the most well known self-assembled monolayers (SAMs) are alkyl sulfides on gold surfaces.  They have many potential applications in molecular electronics, biosensors, and nanopatterning.  However, there have still been unsolved problems in basic research regarding Au-S interaction.  Recently, Professor A. Morgante (Universita' di Trieste, Italy) and his colleagues published the results of grazing incidence X-ray diffraction and density functional theory-based molecular dynamics simulations for hexanethiol and methylthiol.  The research group demonstrated surface complexes wherein two S atoms are joined by an intermediate Au adatom (RS-Au-SR) for longer chain cases. It was found that the sulfur atoms of the molecules bind at two distinct surface sites, and that the first surface layer contains vacancies as well as gold adatoms that are laterally bound to two sulfur atoms.  Competition between SAM ordering and disordering of interfacial Au atoms takes an important role in the system.  For more information, see the paper, "X-ray Diffraction and Computation Yield the Structure of Alkanethiols on Gold(111)", A. Cossaro et al., Science, 321, 943-946 (2008).

3D X-ray image of Ta₂O₅ nanofoams (July 28, 2008)

Aerogel is a form of nanofoam, an engineered material designed for its high strength-to-weight ratio for application wherever lightness and strength are needed.  Now, the internal structure is within the scope of X-ray analysis.  Lawrence Livermore and Lawrence Berkeley scientists have successfully applied the coherent X-ray diffraction technique to Ta₂O₅ nanofoam, the density of which is 1.2 % to the bulk, and have reconstructed 3D images to determine its strength and potential new applications.  Combining the obtained structural information with detailed simulations, the research team showed that the blob-and-beam network structure explains why the materials are weaker than expected.  For more information, see the paper, "Three-Dimensional Coherent X-Ray Diffraction Imaging of a Ceramic Nanofoam: Determination of Structural Deformation Mechanisms", A. Barty et al., Phys. Rev. Lett., 101, 055501 (2008). 

X-ray standing wave determines Al occupancy in zeolite (June 22, 2008)

Zeolites are microporous crystalline materials, and in the unit cell, the tetrahedrally coordinated Si and Al atoms occupy the so-called crystallographic T-sites.  In addition to their pore size, Al’s occupancy in the specific T-sites is extremely important in catalytic activity.  So far, however, the distribution of Al has remained an unresolved problem.  Recently, Professor J. A. van Bokhoven (ETH Zurich, Switzerland) and his colleagues employed the X-ray standing wave technique to study Al distribution in scolecite (CaAl₂Si₃O₁₀-3H₂O, hydrated calcium aluminum silicate).  They measured the intensity of X-ray fluorescence, Al K, Si K and Ca Kα near the Bragg conditions of (040), (002) and (-402) reflections.  The experiments were done at beamline ID32, ESRF.  For more information, see the paper, "Determining the aluminium occupancy on the active T-sites in zeolites using X-ray standing waves", J. A. van Bokhoven et al., Nature Materials, 7, 551-555 (2008).

Recent successful commissioning of high-power mode at J-PARC 3-GeV rapid cycling synchrotron (September 19, 2008)

The J-PARC (Japan Proton Accelerator Research Complex, Tokai, Japan) is a new facility with MW-class high power proton beams at both 3 GeV and 50 GeV.  At the end of May 2008, the first neutron was produced successfully by proton-beam induced spallation reaction at the Materials and Life Science Experimental Facility (MLF).  Furthermore, very recently, the facility succeeded in commissioning high-power operation.  Its 3-GeV rapid cycling synchrotron (RCS) is said to have achieved a beam power of 210 kW for a period of 70 seconds at 25Hz, and 315kW-equivalent power in one-pulse operation.  For more information, visit the Web page, http://j-parc.jp/index-e.html

Brookhaven synchrotron catalysis consortium receives 3-year funding renewal (August 12, 2008)

At Brookhaven, USA, the synchrotron catalysis consortium (SCC) promotes the utilization of synchrotron techniques to perform cutting-edge catalysis nanoscience research.  The activities include dedicated beam time for X-ray absorption spectroscopy experiments at beamlines X18B and X19A at the National Synchrotron Light Source, the assistance of research staff in the set-up of experiments and data analysis, training courses and help sessions etc.  Recently, the U.S. Department of Energy has decided to renew a three-year, $1 million grant.  For more information, visit the Web page, http://www.nsls.bnl.gov/newsroom/news/

Denver X-ray conference awards (August 6, 2008)

Oxford Instruments launches a hand-held XRF analyzer with silicon drift detector (September 22, 2008)

Oxford Instruments has released its new X-MET5100 X-ray fluorescence (XRF) analyzer, which combines a silicon drift detector with a powerful 45kV X-ray tube.  The instrument enables light elements such as Mg, Al and Si to be measured without the need for complex vacuum pump or helium tank attachments.  For more information, visit the Web page, http://www.oxinst.com/
 

PANalytical’s MiniPal 4 Sulfur adapted to new fuel regulations (August 12, 2008)

European Union (EU) countries are facing the introduction of the new Euro V regulations, with their 10 ppm limit on sulfur in ultra low sulfur diesel (ULSD), in January 2009. Through a series of incentives and local initiatives, many EU countries already comply with the standard. In the US, the EPA (Environmental Protection Agency) has mandated the reduction of sulfur content in ULSD to 15 ppm. All highway diesels must meet this standard by December 2010.  PANalytical’s compact EDXRF spectrometer - MiniPal 4 Sulfur - has been designed for quality control and for monitoring the sulfur concentration level in diesel fuels.  The instrument employs a 15 kV silver anode tube that avoids overlap with sulfur signals, and a new silicon drift detector.  For more information, visit the Web page, http://www.panalytical.com/

EDAX releases software for accurate element identification (August 7, 2008)

In X-ray analysis, correct identification of the peaks in the spectrum is indispensable.  Most peak identification routines usually use a rules-based algorithm, which at best provides reasonable accuracy.  So far, such routines have employed some form of peak simulation to overlay the spectrum to provide a visual confirmation that the peak identification is acceptable.  In order to further enhance accuracy in quantitative analysis, EDAX has recently released a new element identification routine, EXpert ID.  For more information, visit the Web page, http://www.edax.com/  EDAX is a unit of AMETEK Materials Analysis Division.

Bruker unveils first handheld XRF spectrometer (June 25, 2008)

Bruker AXS Handheld Inc. has announced the release of the TRACERturboSD, a handheld X-ray fluorescence instrument that features a silicon drift detector.  For further information, visit the web page, http://www.bruker-axs.de/

Rigaku introduces Supermini, a high power benchtop WD-XRF spectrometer (May 8, 2008)

Rigaku Americas Corporation has announced the introduction of a high-power benchtop wavelength dispersive X-ray fluorescence (WDXRF) spectrometer system, the Rigaku Supermini.  The spectrometer employs an air-cooled 50 kV, 200W tube, three analyzing crystals, two detectors, a 12-position sample changer and a choice of analysis in an airmirror_www, vacuum or helium (He) atmosphere.  For further information, contact Thomas F. McNulty, Phone: +1-281-362-2300 Ext207, tom.mcnulty@rigaku.com, or visit the Web page, http://www.rigaku.com/

Bruker acquires AFM company, SIS (August 18, 2008)

Bruker AXS has announced that it has signed an agreement to acquire all of the equity of Surface Imaging Systems (SIS), a company with annual revenues of approximately $3 million.  The transaction is expected to close in the third quarter of 2008.  SIS is located in Herzogenrath, near Aachen, Germany, and has developed atomic force/scanning probe microscopy systems or AFM/SPM, a well-established method for ultra-high spatial resolution surface imaging and characterization of surfaces down to atomic dimensions.  SIS will be renamed Bruker Nano GmbH.  For further information, contact Michael Willett, Investor Relations and Public Relations Officer, Phone: +1-978- 663-3660, ext. 1411, Michael.Willett@bruker.com or visit the web page, http://www.bruker-axs.de/

Thermo Fisher Scientific acquires FIBERLite Centrifuge, Inc. (July 28, 2008)

Thermo Fisher Scientific Inc. has announced that it has acquired FIBERLite Centrifuge, Inc., of Santa Clara, California. FIBERLite is a supplier of carbon fiber centrifuge rotors, which are considered as a promising lightweight alternative for traditional metal rotors.  For further information, visit the Web page, http://www.thermo.com/

SpectroscopyNow.com

For additional news about X-ray analysis and other spectroscopy sciences, browse the Wiley website.

Kenji Sakurai
Director, X-Ray Physics Group, National Institute for
Materials Science (NIMS)
and Professor, Doctoral Program in Materials Science and
Engineering, Graduate School of Pure and Applied Sciences,
 University of Tsukuba
1-2-1, Sengen, Tsukuba, Ibaraki 305-0047 Japan
Phone : +81-29-859-2821, Fax : +81-29-859-2801
sakurai@yuhgiri.nims.go.jp
http://www.nims.go.jp/xray/lab/