As of December 7, 2011

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

Observation of non-linear resonances of inner-shell electrons by X-ray free electron laser (November 30, 2011)

Recently, a very stimulating paper has been published discussing experimentally the fundamental processes of photo-absorption and excitation of electrons by using extremely high-fluence, ultra-short X-ray pulses.  The research was done for the electron system in inert Ne gas at LCLS (Linac Coherent Light Source), Stanford, USA, which is the world’s first hard X-ray free-electron laser facility.  The scheme is as follows: an intense single X-ray pulse of sub-10-fs duration at 848 eV first strips a 2p electron from Ne and, at this stage, since the X-ray energy is below the binding energy of a 1s electron in neutral neon, 870 eV, a 1s hole cannot be produced, but because of the above 2p hole, the next pulse can excite the 1s electron, leading to 1s-2p resonance in the Ne⁺ ion and, finally, stimulated emission (2p-1s) competes with Auger decay to refill the 1s hole.  The results have indicated that intense X-ray pulses of sub-10-fs duration can modify and even control the Auger decay process.  For more information, see the paper, "Unveiling and Driving Hidden Resonances with High-Fluence, High-Intensity X-Ray Pulses", E. P. Kanter et al., Phys. Rev. Lett. 107, 233001 (2011).

Soft X-ray absorption spectroscopy aids understanding on ferroelectric BaTiO₃ (November 28, 2011)

BaTiO₃ is a promising candidate ferroelectric material for magnetoelectric composites and layered film structures.  Recently, some interesting soft X-ray absorption spectra at Ti-L_{II, III} , O-K, and Ba-M_{IV, V} edges have been discussed mainly from a theoretical point of view by a German group.  For more information, see the paper, "High-resolution x-ray absorption spectroscopy of BaTiO₃: Experiment and first-principles calculations", A. Chassֺé et al., Phys. Rev. B84, 195135 (2011).

Theory for multi-wavelength anomalous diffraction with X-ray free electron laser (November 14, 2011)

Multi-wavelength anomalous diffraction (MAD) has been widely employed to determine phase information in X-ray crystallography.  The method uses the contrast of the scattering power of heavy atoms at the absorption edges.  However, when the X-ray source becomes extremely brilliant, the sample encounters severe electronic radiation damage, especially to heavy atoms, which makes the interpretation of MAD rather difficult.  Recently, a theoretical paper discussing this problem has been published.  The theory uses a Karle-Hendrickson-type equation in the high-intensity regime, and demonstrates the calculation of relevant coefficients with detailed electronic damage dynamics of heavy atoms.  For more information, see the paper, "Multiwavelength Anomalous Diffraction at High X-Ray Intensity", S-K.Son et al., Phys. Rev. Lett. 107, 218102 (2011).
 

Monochromator optics for sub-meV resolution (November 11, 2011)

Scientists at Argonne National Laboratory, USA have recently reported a novel set of optics for X-ray monochromators, which combine the effect of angular dispersion and anomalous transmission of X-rays in Bragg reflection from asymmetrically cut crystals.  The optics employ a five-reflection, three-crystal arrangement, and it was found that the spectral contrast, the bandwidth and the angular acceptance are approximately 500, 0.5 meV, and 0.1 mrad, respectively, for 9.1 keV X-rays.  The new optics could be a foundation for next-generation inelastic X-ray scattering spectrometers.  For more information, see the paper, "Using angular dispersion and anomalous transmission to shape ultramonochromatic x rays", Y. Shvyd’ko et al., Phys. Rev. A84, 053823 (2011).
 

Combination of ptychography and near-edge resonance (November 8, 2011)

One of the key aspects of progress in X-ray microscopy is the advent of coherent diffractive imaging, which basically does not use any lenses.  Ptychography is one improved version of a series of techniques using coherent X-ray beams and allows reconstructions of both strongly and weakly scattering samples.  A further extension of this method has recently been published by a German group led by Professor T. Salditt (Georg-August-University Göttingen).  The research introduced chemical contrasts based on near-edge X-ray absorption fine structures.  The group demonstrated that two different molecules in a biological system are distinguished visually by using the contrasts near the oxygen K edge.  For more information, see the paper, "Chemical Contrast in Soft X-Ray Ptychography", M. Beckers et al., Phys. Rev. Lett. 107, 208101 (2011).
 

Mini electron-probe X-ray fluorescence instrument (October 21, 2011)

Professor J. Kawai (Kyoto University, Japan; Associate editor of X-ray Spectrometry) and his colleagues recently developed a novel tiny X-ray instrument equipped with a pyroelectric LiTaO₃ crystal as an electron source, a sample stage and an X-ray detector.  The research group found that adequate X-ray fluorescence spectra can be measured for 0.03 mm² titanium, iron, and nickel wires.  For more information, see the paper, "Development of Miniaturized Electron Probe X-ray Microanalyzer", S. Imashuku et al., Anal. Chem., 83, 8363 (2011).
 

Influence of pH treatment on Kβ/Kα intensity ratio in ZnCo alloys (October 18, 2011)

Empirical and semiempirical K-shell fluorescence yields (ωK) and Kβ/Kα intensity ratios for ZnCo alloy with various chemical compositions, leading to differences in pH, have recently been published.  The samples were excited by 59.5-keV γ rays from a ²⁴¹Am annular radioactive source, and X ray fluorescence spectra were measured by an Ultra-LEGe detector.  For more information, see the paper, "Effect of pH treatment on K-shell x-ray intensity ratios and K-shell x-ray-production cross sections in ZnCo alloys", N. Kup Aylikci et al., Phys. Rev. A84, 042509 (2011).
 

Quantitative synchrotron X-ray fluorescence analysis of buried nanolayer (October 3, 2011)

A German group led by Dr. B. Beckhoff (Physikalisch-Technische Bundesanstalt (PTB), Berlin) recently analyzed quantitatively the buried B₄C nanolayer on a silicon substrate by using synchrotron radiation at BESSY II.  The thickness and elemental composition were successfully determined by reference-free X-ray fluorescence spectrometry under conventional and grazing-incidence conditions.  For more information, see the paper, "Complementary Characterization of Buried Nanolayers by Quantitative X-ray Fluorescence Spectrometry under Conventional and Grazing Incidence Conditions", R. Unterumsberger et al., Anal. Chem., 83, 8623 (2011).
 

Coherent X-ray diffraction to look at stress in nano particles (September 25, 2011)

A research team led by Professor I. Robinson (London Centre for Nanotechnology, University College London) recently analyzed how gold nanocrystal changes after the adsorption of organic molecules because of the strain field.  So far, it has been difficult to observe such influence of adsorbed molecules on the particle structure.  The team employed the coherent X-ray diffraction method, which is extremely sensitive to displacement of atoms, and therefore to adsorption-induced near-surface stress in a single nanocrystal.  It was discovered that the stress generated by thiol adsorption on gold has a fundamentally different nature in the curved, nominally spherical, regions of the crystal surface than in its flat facets.  The magnitude of surface stress was also quantitatively analyzed and discussed.  The experiments were done with coherent X-rays of 8.92 keV from the 34-ID-C beamline of the Advanced Photon Source (APS), Argonne, USA.  For more information, see the paper, "Differential stress induced by thiol adsorption on facetted nanocrystals", M. Watari et al., Nature Materials 10, 862 (2011).
 

Synchrotron X-ray analysis of an unfinished self-portrait by Rembrandt van Rijn (December 2, 2011)

On Friday 2 December 2011, an unknown painting by Rembrandt was presented in the Rembrandt House Museum (Amsterdam).  The small panel, Old Man with a Beard, was painted by Rembrandt around 1630, at the end of his time in Leiden.  A research group led by Professor K. Janssens (University of Antwerp) and Professor J. Dik (Delft University of Technology) has performed experimental studies on this painting with a synchrotron beam at the European Synchrotron Radiation Facility (ESRF) and the Brookhaven National Laboratory (BNL), and has unveiled a hidden, unfinished self-portrait below the painting.  For further information, visit the web page, http://webh01.ua.ac.be/mitac4/rembrandt/index_301111.html
 

The 6th Asada award (October 28, 2011)

The recipient of the 6th Asada Award, which is presented by the Discussion Group of X-ray Analysis, Japan, in memory of the late Professor Ei-ichi Asada (1924-2005) to promising young scientists in X-ray analysis fields in Japan, is Dr. Takashi Yamamoto (Tokushima Univ., "Studies on pre-edge peak in XANES spectra of transition metals for empirical chemical state analysis").  The ceremony was held during the 47th Annual Conference on X-Ray Chemical Analysis, Japan, at Kyushu University, Fukuoka.
 

MOU between European XFEL and Spanish laser institute (October 10, 2011)

European XFEL and the Spanish Center for Ultrashort Ultraintense Pulsed Lasers (CLPU) in Salamanca will pool their efforts to promote research into high-energy density science and to develop new ultrafast lasers to analyze physical and chemical processes in conjunction with the X-ray beams of the European XFEL.  Both research institutions signed a memorandum of understanding at the European XFEL headquarters in Hamburg.  In the framework of this cooperation, an optical laser expert from CLPU has now joined the European XFEL Optical Lasers Group for an initial period of six months.  For further information, visit the web page,  http://www.xfel.eu/
 

New handheld XRF spectrometer from Oxford Instruments (November 14, 2011)

Oxford Instruments has released a new faster, lighter and smaller handheld XRF analyzer - the X MET7000, which is designed for industrial markets, including PMI, metals and alloys, scrap sorting and precious metals analysis.  For further information, visit the web page, http://www.oxinst.com/
 

Collaboration between Bruker and Symphony Environmental on the XRF analysis of plastic (November 23, 2011)

After a one year cooperative development, Bruker Corporation and Symphony Environmental Ltd have signed a contract for the exclusive supply of Bruker’s X-Ray Fluorescence (XRF) technology to Symphony for the identification of pro-degradant, anti-microbial and anti-fungal additives in plastic.  For further information, visit the web page, http://www.bruker-axs.com/
 

JEOL ASEAN Technical Center in Thailand (November 2, 2011)

JEOL Ltd. has announced a plan to open the JEOL ASEAN Technical Center, in Thailand.  The center will launch in January 2012.  For further information, visit the web page,  http://www.jeol.com/
 

Rigaku acquires handheld Raman products from BaySpec (October 13, 2011)

Rigaku Americas Corporation has announced the acquisition of the handheld Raman technology and product lines from BaySpec, Inc. and the concurrent formation of a new division, Rigaku Raman Technologies Inc., for R&D, engineering, production, marketing and distribution.  For further information, visit the web page, http://www.rigaku.com/
 

Horiba’s new facility in Paris (September 16, 2011)

Horiba has launched a new facility for R&D in the Paris Saclay cluster.  For further information, visit the web page, http://www.horiba.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/