Interpretation of linear dichroism at S L2,3 x-ray absorption edges of small organic molecules at surfaces

Absorption spectra of two orthogonal linearly polarized x-rays in a single CeCoGe3 crystal were measured at the ID12 beamline of the ESRF for the energies near the K-edges of Ge, Co and near the L23 edges of Ce. The X-ray natural linear dichroism (XNLD) was revealed in the vicinity of all the absorption edges, which indicates a splitting of electronic states in a crystalline field. Mathematical modelling in comparison with experimental data allowed the isotropic and anisotropic parts of atomic absorption cross section in CeCoGe3 to be determined near all measured absorption edges. The calculations also show that the “average” anisotropy of the cross section close to the Ge K-edge revealed in the experiment is less than the partial anisotropic contributions corresponding to Ge atoms in two different Wyckoff positions.

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Microwave-assisted synthesis of water-soluble, fluorescent gold nanoclusters capped with small organic molecules and a revealing fluorescence and X-ray absorption study

Nanoscale ◽

10.1039/c4nr07051h ◽

2015 ◽

Vol 7 (11) ◽

pp. 4978-4983 ◽

Cited By ~ 11

Author(s):

C. Helmbrecht ◽

D. Lützenkirchen-Hecht ◽

W. Frank

Keyword(s):

Organic Molecules ◽

Gold Nanoclusters ◽

Water Soluble ◽

Microwave Assisted Synthesis ◽

Absorption Study ◽

Small Organic Molecules ◽

X Ray ◽

Microwave Assisted ◽

X Ray Absorption

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Spectroscopic analysis of small organic molecules: A comprehensive near-edge x-ray-absorption fine-structure study of C6-ring-containing molecules

The Journal of Chemical Physics ◽

10.1063/1.2139674 ◽

2006 ◽

Vol 124 (3) ◽

pp. 034302 ◽

Cited By ~ 39

Author(s):

C. Kolczewski ◽

R. Püttner ◽

M. Martins ◽

A. S. Schlachter ◽

G. Snell ◽

...

Keyword(s):

Fine Structure ◽

Organic Molecules ◽

Spectroscopic Analysis ◽

Structure Study ◽

Small Organic Molecules ◽

X Ray ◽

Absorption Fine ◽

X Ray Absorption

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Al-driven peculiarities of local coordination and magnetic properties in single-phase Alx-CrFeCoNi high-entropy alloys

Nano Research ◽

10.1007/s12274-021-3704-5 ◽

2021 ◽

Author(s):

Alevtina Smekhova ◽

Alexei Kuzmin ◽

Konrad Siemensmeyer ◽

Chen Luo ◽

Kai Chen ◽

...

Keyword(s):

Magnetic Properties ◽

Single Phase ◽

Magnetic Circular Dichroism ◽

Surface Region ◽

Face Centered Cubic ◽

X Rays ◽

X Ray ◽

High Entropy ◽

X Ray Absorption ◽

Absorption Edges

AbstractModern design of superior multi-functional alloys composed of several principal components requires in-depth studies of their local structure for developing desired macroscopic properties. Herein, peculiarities of atomic arrangements on the local scale and electronic states of constituent elements in the single-phase face-centered cubic (fcc)- and body-centered cubic (bcc)-structured high-entropy Alx-CrFeCoNi alloys (x = 0.3 and 3, respectively) are explored by element-specific X-ray absorption spectroscopy in hard and soft X-ray energy ranges. Simulations based on the reverse Monte Carlo approach allow to perform a simultaneous fit of extended X-ray absorption fine structure spectra recorded at K absorption edges of each 3d constituent and to reconstruct the local environment within the first coordination shells of absorbers with high precision. The revealed unimodal and bimodal distributions of all five elements are in agreement with structure-dependent magnetic properties of studied alloys probed by magnetometry. A degree of surface atoms oxidation uncovered by soft X-rays suggests different kinetics of oxide formation for each type of constituents and has to be taken into account. X-ray magnetic circular dichroism technique employed at L2.3 absorption edges of transition metals demonstrates reduced magnetic moments of 3d metal constituents in the sub-surface region of in situ cleaned fcc-structured Al0.3-CrFeCoNi compared to their bulk values. Extended to nanostructured versions of multicomponent alloys, such studies would bring new insights related to effects of high entropy mixing on low dimensions.

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X-RAY ABSORPTION EDGES OF TRANSITION- METAL-DOPED Y1Ba2Cu3−xMxO7−∂

International Journal of Modern Physics B ◽

10.1142/s0217979288001037 ◽

1988 ◽

Vol 02 (05) ◽

pp. 1153-1156 ◽

Cited By ~ 1

Author(s):

J. B. BOYCE ◽

F. BRIDGES ◽

T. CLAESON ◽

T. H. GEBALLE ◽

M. NYGREN ◽

...

Keyword(s):

Transition Metal ◽

X Ray ◽

Metal Doped ◽

X Ray Absorption ◽

Absorption Edges

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A single crystal, linearly polarized Fe 2p X-ray absorption study of gillespite

Mineralogical Magazine ◽

10.1180/002646198547477 ◽

1998 ◽

Vol 62 (1) ◽

pp. 65-75 ◽

Cited By ~ 7

Author(s):

P. F. Schofield ◽

G. van der Laan ◽

C. M. B. Henderson ◽

G. Cressey

Keyword(s):

Single Crystal ◽

Ground State ◽

Branching Ratio ◽

Linear Dichroism ◽

Electronic Charge ◽

Magic Angle ◽

X Rays ◽

X Ray ◽

Peak Structure ◽

X Ray Absorption

AbstractThe Fe 2p X-ray absorption spectra of single crystal gillespite, BaFeSi4O10, show a strong linear dichroism, i.e. a large difference in the absorption when measured with the polarization of the X-rays either parallel or perpendicular to the plane of the FeO4 group. The isotropic spectrum, obtained from measurement at the ‘magic angle’, and the polarization dependent spectra have been compared to atomic multiplet calculations and show an excellent agreement with theory. Analysis of the branching ratio, the linear dichroism, and the detailed peak structure confirms that the 5A1 level is the ground state at room temperature and pressure. The 5B2 level is sufficiently low in energy that a distortion of the electronic charge density, induced by increased pressure, may result in a 5B2 ground state.

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X-ray magnetic circular dichroism study of SmAl2 using the M4,5 x-ray absorption edges

Journal of Applied Physics ◽

10.1063/1.1556275 ◽

2003 ◽

Vol 93 (10) ◽

pp. 8337-8339 ◽

Cited By ~ 3

Author(s):

S. S. Dhesi ◽

P. Bencok ◽

N. B. Brookes ◽

G. van der Laan ◽

R. M. Galéra

Keyword(s):

Circular Dichroism ◽

Magnetic Circular Dichroism ◽

X Ray ◽

X Ray Absorption ◽

Circular Dichroïsm ◽

Absorption Edges

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Near Edge X-Ray Absorption Fine Structure (NEXAFS) Microscopy: Chemical Analysis at Sub Visible Spatial Resolution

Microscopy and Microanalysis ◽

10.1017/s1431927600011144 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 851-852

Author(s):

H. Ade

Keyword(s):

Fine Structure ◽

Compositional Analysis ◽

High Sensitivity ◽

Linear Dichroism ◽

X Rays ◽

X Ray ◽

Absorption Fine ◽

Nexafs Spectroscopy ◽

Wide Range ◽

X Ray Absorption

Infrared, Raman, and fluorescence/luminescence microspectroscopy/microscopy in many instances seek to provide high sensitivity compositional and functional information that goes beyond mere elemental composition. This goal is shared by NEXAFS microscopy, in which Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy is employed to provide chemical sensitivity and can be relatively easily adopted in a scanning transmission x-ray microscope (STXM). In addition to compositional information, NEXAFS microscopy can exploit the dependence of x-ray absorption resonances on the bond orientation relative to the linearly polarized x rays (linear dichroism microscopy). For compositional analysis, NEXAFS microscopy is analogous to Electron Energy Loss Spectroscopy (EELS) in an electron microscope. However, when utilizing near edge spectral features, NEXAFS microscopy requires a considerable lower dose than EELS microscopy which makes it very suitable to studying radiation sensitive materials such as polymers. NEXAFS has shown to have excellent sensitivity to a wide range of moieties in polymers, including sensitivity to substitution isomerism.

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