共查询到20条相似文献,搜索用时 12 毫秒
1.
Cinthia Piamonteze Uwe Flechsig Stefano Rusponi Jan Dreiser Jakoba Heidler Marcus Schmidt Reto Wetter Marco Calvi Thomas Schmidt Helena Pruchova Juraj Krempasky Christoph Quitmann Harald Brune Frithjof Nolting 《Journal of synchrotron radiation》2012,19(5):661-674
X‐Treme is a soft X‐ray beamline recently built in the Swiss Light Source at the Paul Scherrer Institut in collaboration with École Polytechnique Fédérale de Lausanne. The beamline is dedicated to polarization‐dependent X‐ray absorption spectroscopy at high magnetic fields and low temperature. The source is an elliptically polarizing undulator. The end‐station has a superconducting 7 T–2 T vector magnet, with sample temperature down to 2 K and is equipped with an in situ sample preparation system for surface science. The beamline commissioning measurements, which show a resolving power of 8000 and a maximum flux at the sample of 4.7 × 1012 photons s?1, are presented. Scientific examples showing X‐ray magnetic circular and X‐ray magnetic linear dichroism measurements are also presented. 相似文献
2.
Jesús Chaboy María ángeles Laguna‐Marco Cristina Piquer Roberto Boada Neculai Plugaru Hiroshi Maruyama Naomi Kawamura 《Journal of synchrotron radiation》2009,16(3):405-412
An X‐ray magnetic circular dichroism (XMCD) study performed at the rare‐earth L2,3‐edges in the RxR1?x′Al2 compounds is presented. It is shown that both R and R′ atoms contribute to the XMCD recorded at the L‐edges of the selected rare‐earth, either R or R′. The amplitude of the XMCD signal is not directly correlated to the magnetization or to the value of the individual (R, R′) magnetic moments, but it is related to the molecular field acting on the rare‐earth tuned in the photoabsorption process. This result closes a longstanding study of the origin of the XMCD at the L‐edge of the rare‐earths in multi‐component systems, allowing a full understanding of the exact nature of these signals. 相似文献
3.
J. Goulon A. Rogalev F. Wilhelm Ch. Goulon‐Ginet G. Goujon 《Journal of synchrotron radiation》2007,14(3):257-271
X‐ray detected magnetic resonance (XDMR) is a new element‐selective spectroscopy in which X‐ray magnetic circular dichroism is used to probe the resonant precession of spin and orbital magnetization components when a strong microwave pump field is applied perpendicularly to the static bias field. Experimental configurations suitable for detecting the very weak XDMR signal are compared. XDMR signatures were measured in yttrium iron garnet and related thin films on exciting not only the iron K‐edge but also the yttrium at diamagnetic sites. These measurements are shown to yield unique information regarding the wide‐angle precession of induced magnetization components involving either orbital p‐projected densities of states at the iron sites, or spin polarized d‐projected densities of states at the yttrium sites. Extending XDMR measurements into the millimeter wave range would make it possible to study paramagnetic systems routinely and investigate optical modes as well as acoustic modes in ferrimagnetic/antiferromagnetic systems. 相似文献
4.
Design and performance of BOREAS,the beamline for resonant X‐ray absorption and scattering experiments at the ALBA synchrotron light source
下载免费PDF全文
![点击此处可从《Journal of synchrotron radiation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Alessandro Barla Josep Nicolás Daniele Cocco Secundino Manuel Valvidares Javier Herrero-Martín Pierluigi Gargiani Jairo Moldes Claude Ruget Eric Pellegrin Salvador Ferrer 《Journal of synchrotron radiation》2016,23(6):1507-1517
The optical design of the BOREAS beamline operating at the ALBA synchrotron radiation facility is described. BOREAS is dedicated to resonant X‐ray absorption and scattering experiments using soft X‐rays, in an unusually extended photon energy range from 80 to above 4000 eV, and with full polarization control. Its optical scheme includes a fixed‐included‐angle, variable‐line‐spacing grating monochromator and a pair of refocusing mirrors, equipped with benders, in a Kirkpatrick–Baez arrangement. It is equipped with two end‐stations, one for X‐ray magnetic circular dichroism and the other for resonant magnetic scattering. The commissioning results show that the expected beamline performance is achieved both in terms of energy resolution and of photon flux at the sample position. 相似文献
5.
A compact permanent‐magnet system for measuring magnetic circular dichroism in resonant inelastic soft X‐ray scattering
下载免费PDF全文
![点击此处可从《Journal of synchrotron radiation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jun Miyawaki Shigemasa Suga Hidenori Fujiwara Hideharu Niwa Hisao Kiuchi Yoshihisa Harada 《Journal of synchrotron radiation》2017,24(2):449-455
A compact and portable magnet system for measuring magnetic dichroism in resonant inelastic soft X‐ray scattering (SX‐RIXS) has been developed at the beamline BL07LSU in SPring‐8. A magnetic circuit composed of Nd–Fe–B permanent magnets, which realised ~0.25 T at the center of an 11 mm gap, was rotatable around the axis perpendicular to the X‐ray scattering plane. Using the system, a SX‐RIXS spectrum was obtained under the application of the magnetic field at an angle parallel, nearly 45° or perpendicular to the incident X‐rays. A dedicated sample stage was also designed to be as compact as possible, making it possible to perform SX‐RIXS measurements at arbitrary incident angles by rotating the sample stage in the gap between the magnetic poles. This system enables facile studies of magnetic dichroism in SX‐RIXS for various experimental geometries of the sample and the magnetic field. A brief demonstration of the application is presented. 相似文献
6.
Single‐crystal X‐ray diffraction and resonant X‐ray magnetic scattering at helium‐3 temperatures in high magnetic fields at beamline P09 at PETRA III
下载免费PDF全文
![点击此处可从《Journal of synchrotron radiation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
S. Francoual J. Strempfer J. Warren Y. Liu A. Skaugen S. Poli J. Blume F. Wolff‐Fabris P. C. Canfield T. Lograsso 《Journal of synchrotron radiation》2015,22(5):1207-1214
The resonant scattering and diffraction beamline P09 at PETRA III at DESY is equipped with a 14 T vertical field split‐pair magnet. A helium‐3 refrigerator is available that can be fitted inside the magnet's variable‐temperature insert. Here the results of a series of experiments aimed at determining the beam conditions permitting operations with the He‐3 insert are presented. By measuring the tetragonal‐to‐orthorhombic phase transition occurring at 2.1 K in the Jahn–Teller compound TmVO4, it is found that the photon flux at P09 must be attenuated down to 1.5 × 109 photons s?1 for the sample to remain at temperatures below 800 mK. Despite such a reduction of the incident flux and the subsequent use of a Cu(111) analyzer, the resonant X‐ray magnetic scattering signal at the Tm LIII absorption edge associated with the spin‐density wave in TmNi2B2C below 1.5 K is intense enough to permit a complete study in magnetic field and at sub‐Kelvin temperatures to be carried out. 相似文献
7.
《Current Applied Physics》2018,18(11):1182-1184
The combination of angular spin momentum with electronics is a promising successor to charge-based electronics. The conduction bands in GaAs may become spin-polarized via optical spin pumping, doping with magnetic ions, or induction of a moment with an external magnetic field. We investigated the spin populations in GaAs with x-ray magnetic circular dichroism for each of these three cases. We find strong anti-symmetric lineshapes at the Ga L3 edge indicating conduction band spin splitting, with differences in line width and amplitude depending on the source of spin polarization. 相似文献
8.
Picosecond‐resolved X‐ray absorption spectroscopy at low signal contrast using a hard X‐ray streak camera
下载免费PDF全文
![点击此处可从《Journal of synchrotron radiation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Bernhard W. Adams Christoph Rose‐Petruck Yishuo Jiao 《Journal of synchrotron radiation》2015,22(4):1022-1029
A picosecond‐resolving hard‐X‐ray streak camera has been in operation for several years at Sector 7 of the Advanced Photon Source (APS). Several upgrades have been implemented over the past few years to optimize integration into the beamline, reduce the timing jitter, and improve the signal‐to‐noise ratio. These include the development of X‐ray optics for focusing the X‐rays into the sample and the entrance slit of the streak camera, and measures to minimize the amount of laser light needed to generate the deflection‐voltage ramp. For the latter, the photoconductive switch generating the deflection ramp was replaced with microwave power electronics. With these, the streak camera operates routinely at 88 MHz repetition rate, thus making it compatible with all of the APS fill patterns including use of all the X‐rays in the 324‐bunch mode. Sample data are shown to demonstrate the performance. 相似文献
9.
Jean‐Louis Hazemann Olivier Proux Vivian Nassif Hervé Palancher Eric Lahera Cécile Da Silva Aurélien Braillard Denis Testemale Marie‐Ange Diot Isabelle Alliot William Del Net Alain Manceau Frédéric Gélébart Marc Morand Quentin Dermigny Abhay Shukla 《Journal of synchrotron radiation》2009,16(2):283-292
A bent‐crystal spectrometer based on the Rowland circle geometry has been installed and tested on the BM30b/FAME beamline at the European Synchrotron Radiation Facility to improve its performances. The energy resolution of the spectrometer allows different kinds of measurements to be performed, including X‐ray absorption spectroscopy, resonant inelastic X‐ray scattering and X‐ray Raman scattering experiments. The simplicity of the experimental device makes it easily implemented on a classical X‐ray absorption beamline. This improvement in the fluorescence detection is of particular importance when the probed element is embedded in a complex and/or heavy matrix, for example in environmental sciences. 相似文献
10.
D. Lützenkirchen‐Hecht R. Wagner S. Szillat A. K. Hüsecken K. Istomin U. Pietsch Ronald Frahm 《Journal of synchrotron radiation》2014,21(4):819-826
The layout and the characteristics of the hard X‐ray beamline BL10 at the superconducting asymmetric wiggler at the 1.5 GeV Dortmund Electron Accelerator DELTA are described. This beamline is equipped with a Si(111) channel‐cut monochromator and is dedicated to X‐ray studies in the spectral range from ~4 keV to ~16 keV photon energy. There are two different endstations available. While X‐ray absorption studies in different detection modes (transmission, fluorescence, reflectivity) can be performed on a designated table, a six‐axis kappa diffractometer is installed for X‐ray scattering and reflectivity experiments. Different detector set‐ups are integrated into the beamline control software, i.e. gas‐filled ionization chambers, different photodiodes, as well as a Pilatus 2D‐detector are permanently available. The performance of the beamline is illustrated by high‐quality X‐ray absorption spectra from several reference compounds. First applications include temperature‐dependent EXAFS experiments from liquid‐nitrogen temperature in a bath cryostat up to ~660 K by using a dedicated furnace. Besides transmission measurements, fluorescence detection for dilute sample systems as well as surface‐sensitive reflection‐mode experiments are presented. 相似文献
11.
Naomi Kawamura Naoki Ishimatsu Hiroshi Maruyama 《Journal of synchrotron radiation》2009,16(6):730-736
An X‐ray magnetic circular dichroism experiment under multiple extreme conditions, 2 ≤T≤ 300 K, H≤ 10 T and P≤ 50 GPa, has been achieved at SPring‐8 BL39XU. A combination of the high‐brilliant X‐ray beam and a helicity‐controlled technique enabled the dichroic signal to be recorded with high accuracy. The performance is shown by the outcome of pressure‐induced ferromagnetism in Mn3GaC and the pressure‐suppressed Co moment in ErCo2. Two technical developments, a tiny diamond anvil cell inserted into a superconducting magnet and in situ pressure calibration using 90° Bragg diffraction from a NaCl marker, are also presented. X‐ray magnetic spectroscopy under multiple extreme conditions is now opening a new approach to materials science. 相似文献
12.
Development of picosecond time‐resolved X‐ray absorption spectroscopy by high‐repetition‐rate laser pump/X‐ray probe at Beijing Synchrotron Radiation Facility
下载免费PDF全文
![点击此处可从《Journal of synchrotron radiation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hao Wang Can Yu Xu Wei Zhenhua Gao Guang-Lei Xu Da-Rui Sun Zhenjie Li Yangfan Zhou Qiu-Ju Li Bing-Bing Zhang Jin-Qiang Xu Lin Wang Yan Zhang Ying-Lei Tan Ye Tao 《Journal of synchrotron radiation》2017,24(3):667-673
A new setup and commissioning of transient X‐ray absorption spectroscopy are described, based on the high‐repetition‐rate laser pump/X‐ray probe method, at the 1W2B wiggler beamline at the Beijing Synchrotron Radiation Facility. A high‐repetition‐rate and high‐power laser is incorporated into the setup with in‐house‐built avalanche photodiodes as detectors. A simple acquisition scheme was applied to obtain laser‐on and laser‐off signals simultaneously. The capability of picosecond transient X‐ray absorption spectroscopy measurement was demonstrated for a photo‐induced spin‐crossover iron complex in 6 mM solution with 155 kHz repetition rate. 相似文献
13.
Edmund Welter Karsten Hansen Christian Reckleben Inge Diehl 《Journal of synchrotron radiation》2009,16(2):293-298
In this paper results are presented from fluorescence‐yield X‐ray absorption fine‐structure spectroscopy measurements with a new seven‐cell silicon drift detector (SDD) module. The complete module, including an integrated circuit for the detector readout, was developed and realised at DESY utilizing a monolithic seven‐cell SDD. The new detector module is optimized for applications like XAFS which require an energy resolution of ~250–300 eV (FWHM Mn Kα) at high count rates. Measurements during the commissioning phase proved the excellent performance for this type of application. 相似文献
14.
Yuya Shinohara Akira Watanabe Hiroyuki Kishimoto Yoshiyuki Amemiya 《Journal of synchrotron radiation》2013,20(5):801-804
Combined X‐ray photon correlation spectroscopy (XPCS) and diffracted X‐ray tracking (DXT) measurements of carbon‐black nanocrystals embedded in styrene–butadiene rubber were performed. From the intensity fluctuation of speckle patterns in a small‐angle scattering region (XPCS), dynamical information relating to the translational motion can be obtained, and the rotational motion is observed through the changes in the positions of DXT diffraction spots. Graphitized carbon‐black nanocrystals in unvulcanized styrene–butadiene rubber showed an apparent discrepancy between their translational and rotational motions; this result seems to support a stress‐relaxation model for the origin of super‐diffusive particle motion that is widely observed in nanocolloidal systems. Combined measurements using these two techniques will give new insights into nanoscopic dynamics, and will be useful as a microrheology technique. 相似文献
15.
G. Mitrea J. Thieme P. Guttmann S. Heim S. Gleber 《Journal of synchrotron radiation》2008,15(1):26-35
Using the scanning transmission X‐ray microscope at BESSY II, colloidal structures from a Chernozem soil have been studied with a spatial resolution around 60 nm and a spectral resolution of 1700 at the K‐absorption edge of carbon. Elemental mapping has been used to determine the distribution of organic matter within the colloidal structures. Spectra have been extracted from image stacks to obtain information about the chemical state. For the analysis of the latter, principal component analysis and cluster analysis have been applied. It was possible, for example, to discriminate clay particles against organic components. 相似文献
16.
Stefan Buschhorn Frank Brüssing Radu Abrudan Hartmut Zabel 《Journal of synchrotron radiation》2011,18(2):212-216
A new set‐up is presented to measure element‐selective magnetization dynamics using the ALICE chamber [Grabis et al. (2003), Rev. Sci. Instrum. 74 , 4048–4051] at the BESSY II synchrotron at the Helmholtz‐Zentrum Berlin. A magnetic‐field pulse serves as excitation, and the magnetization precession is probed by element‐selective X‐ray resonant magnetic scattering. With the use of single‐bunch‐generated X‐rays a temporal resolution well below 100 ps is reached. The ALICE diffractometer environment enables investigations of thin films, described here, multilayers and laterally structured samples in reflection or diffuse scattering geometry. The combination of the time‐resolved set‐up with a cryostat in the ALICE chamber will allow temperature‐dependent studies of precessional magnetization dynamics and of damping constants to be conducted over a large temperature range and for a large variety of systems in reflection geometry. 相似文献
17.
Simultaneous X‐ray fluorescence and scanning X‐ray diffraction microscopy at the Australian Synchrotron XFM beamline
下载免费PDF全文
![点击此处可从《Journal of synchrotron radiation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Michael W. M. Jones Nicholas W. Phillips Grant A. van Riessen Brian Abbey David J. Vine Youssef S. G. Nashed Stephen T. Mudie Nader Afshar Robin Kirkham Bo Chen Eugeniu Balaur Martin D. de Jonge 《Journal of synchrotron radiation》2016,23(5):1151-1157
Owing to its extreme sensitivity, quantitative mapping of elemental distributions via X‐ray fluorescence microscopy (XFM) has become a key microanalytical technique. The recent realisation of scanning X‐ray diffraction microscopy (SXDM) meanwhile provides an avenue for quantitative super‐resolved ultra‐structural visualization. The similarity of their experimental geometries indicates excellent prospects for simultaneous acquisition. Here, in both step‐ and fly‐scanning modes, robust, simultaneous XFM‐SXDM is demonstrated. 相似文献
18.
Collimating Montel mirror as part of a multi‐crystal analyzer system for resonant inelastic X‐ray scattering
下载免费PDF全文
![点击此处可从《Journal of synchrotron radiation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jungho Kim Xianbo Shi Diego Casa Jun Qian XianRong Huang Thomas Gog 《Journal of synchrotron radiation》2016,23(4):880-886
Advances in resonant inelastic X‐ray scattering (RIXS) have come in lockstep with improvements in energy resolution. Currently, the best energy resolution at the Ir L3‐edge stands at ~25 meV, which is achieved using a diced Si(844) spherical crystal analyzer. However, spherical analyzers are limited by their intrinsic reflection width. A novel analyzer system using multiple flat crystals provides a promising way to overcome this limitation. For the present design, an energy resolution at or below 10 meV was selected. Recognizing that the angular acceptance of flat crystals is severely limited, a collimating element is essential to achieve the necessary solid‐angle acceptance. For this purpose, a laterally graded, parabolic, multilayer Montel mirror was designed for use at the Ir L3‐absorption edge. It provides an acceptance larger than 10 mrad, collimating the reflected X‐ray beam to smaller than 100 µrad, in both vertical and horizontal directions. The performance of this mirror was studied at beamline 27‐ID at the Advanced Photon Source. X‐rays from a diamond (111) monochromator illuminated a scattering source of diameter 5 µm, generating an incident beam on the mirror with a well determined divergence of 40 mrad. A flat Si(111) crystal after the mirror served as the divergence analyzer. From X‐ray measurements, ray‐tracing simulations and optical metrology results, it was established that the Montel mirror satisfied the specifications of angular acceptance and collimation quality necessary for a high‐resolution RIXS multi‐crystal analyzer system. 相似文献
19.
Motohiro Suzuki Yuichi Inubushi Makina Yabashi Tetsuya Ishikawa 《Journal of synchrotron radiation》2014,21(3):466-472
A diamond phase retarder was applied to control the polarization states of a hard X‐ray free‐electron laser (XFEL) in the photon energy range 5–20 keV. The horizontal polarization of the XFEL beam generated from the planar undulators of the SPring‐8 Angstrom Compact Free‐Electron Laser (SACLA) was converted into vertical or circular polarization of either helicity by adjusting the angular offset of the diamond crystal from the exact Bragg condition. Using a 1.5 mm‐thick crystal, a high degree of circular polarization, 97%, was obtained for 11.56 keV monochromatic X‐rays, whereas the degree of vertical polarization was 67%, both of which agreed with the estimations including the energy bandwidth of the Si 111 beamline monochromator. 相似文献
20.
M. K. Tiwari P. Gupta A. K. Sinha S. R. Kane A. K. Singh S. R. Garg C. K. Garg G. S. Lodha S. K. Deb 《Journal of synchrotron radiation》2013,20(2):386-389
A microfocus X‐ray fluorescence spectroscopy beamline (BL‐16) at the Indian synchrotron radiation facility Indus‐2 has been constructed with an experimental emphasis on environmental, archaeological, biomedical and material science applications involving heavy metal speciation and their localization. The beamline offers a combination of different analytical probes, e.g. X‐ray fluorescence mapping, X‐ray microspectroscopy and total‐external‐reflection fluorescence characterization. The beamline is installed on a bending‐magnet source with a working X‐ray energy range of 4–20 keV, enabling it to excite K‐edges of all elements from S to Nb and L‐edges from Ag to U. The optics of the beamline comprises of a double‐crystal monochromator with Si(111) symmetric and asymmetric crystals and a pair of Kirkpatrick–Baez focusing mirrors. This paper describes the performance of the beamline and its capabilities with examples of measured results. 相似文献