X-ray absorption multiple-scattering study of angle distribution in high-Tc superconductors

The valence states of cations inside four high T c thallium superconductors have been investigated by X-ray absorption spectroscopy at thallium LIII , LI and copper K-edges. The thallium ions are observed on LIII and LI edges in the Tl(III) valence state (empty 6s levels) in spite of large Tl-O distances in the (a, b) plane of the structure as deduced from X-ray diffraction. The presence of two types of Tl-O distances have been well established on XANES spectra and the F.T. of EXAFS have shown the presence of two very short Tl-O bonds (2.03 Å). The copper K-edges are characterized by the absence of Cu(I) state (3d10 line).

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Valence characterization and in-situ kinetics of oxygen uptake and removal in high Tc superconductors by X-ray absorption spectroscopy

Journal of the Less Common Metals ◽

10.1016/0022-5088(89)90016-7 ◽

1989 ◽

Vol 148 (1-2) ◽

pp. 97-108 ◽

Cited By ~ 1

Author(s):

A. Fontaine ◽

A.M. Flank ◽

E. Dartyge ◽

P. Lagarde ◽

H. Tolentino ◽

...

Keyword(s):

Oxygen Uptake ◽

Absorption Spectroscopy ◽

High Tc Superconductors ◽

High Tc ◽

X Ray ◽

X Ray Absorption ◽

Kinetics Of

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VanadiumK-edge XANES in vanadium-bearing model compounds: a full multiple scattering study

Journal of Synchrotron Radiation ◽

10.1107/s1600577516008134 ◽

2016 ◽

Vol 23 (4) ◽

pp. 947-952 ◽

Cited By ~ 4

Author(s):

Federico Benzi ◽

Gabriele Giuli ◽

Stefano Della Longa ◽

Eleonora Paris

Keyword(s):

Multiple Scattering ◽

Oxidation States ◽

Coordination Geometry ◽

Framework Analysis ◽

Model Compounds ◽

X Ray ◽

Preliminary Information ◽

Scattering Study ◽

Free Parameters ◽

X Ray Absorption

A systematic study is presented on a set of vanadium-bearing model compounds, representative of the most common V coordination geometries and oxidation states, analysed by means of vanadiumK-edge X-ray absorption near-edge spectroscopy calculations in the full multiple scattering (FMS) framework. Analysis and calibration of the free parameters of the theory under the muffin-tin approximation (muffin-tin overlap and interstitial potential) have been carried out by fitting the experimental spectra using theMXANprogram. The analysis shows a correlation of the fit parameters with the V coordination geometry and oxidation state. By making use of this correlation it is possible to approach the study of unknown V-bearing compounds with useful preliminary information.

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X-ray absorption studies of La2-x(Ba,Sr)xCuO4 high-Tc superconductors

Physica C Superconductivity ◽

10.1016/0921-4534(93)90548-5 ◽

1993 ◽

Vol 209 (4) ◽

pp. 373-380 ◽

Cited By ~ 4

Author(s):

M.J. Akhtar ◽

Z.N. Akhtar ◽

C.R.A. Catlow

Keyword(s):

High Tc Superconductors ◽

High Tc ◽

X Ray ◽

Absorption Studies ◽

X Ray Absorption

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SYMMETRY OF THE HOLE STATES IN BiCaSrCuO HIGH-Tc SUPERCONDUCTORS

Modern Physics Letters B ◽

10.1142/s0217984988001302 ◽

1988 ◽

Vol 02 (11n12) ◽

pp. 1313-1318 ◽

Cited By ~ 22

Author(s):

A. BIANCONI ◽

P. CASTRUCCI ◽

M. DE SANTIS ◽

A. DI CICCO ◽

A. FABRIZI ◽

...

Keyword(s):

Absorption Spectra ◽

Ground State ◽

Superconducting Materials ◽

Molecular Symmetry ◽

High Tc Superconductors ◽

High Tc ◽

X Ray ◽

Oriented Film ◽

X Ray Absorption

Polarized Cu L3-edge X-ray absorption spectra (XAS) of oriented film of Bi 2 Sr 2 Ca 1 Cu 2 O y have been measured to determine the symmetry of the orbital of the electronic holes. The states with the configuration 3d9L (L indicates ligand holes) have been detected. The holes d in superconducting materials are found to be in the antiferromagnetic band with b1 symmetry, derived by the Cu 3dx2 - y2 orbital, but also in a second band with a1 molecular symmetry, derived by Cu 3dz2 - r2 orbital at the Cu site. Our results can be rationalized with the formation of both d (b1) L and d (a1) L states in the ground state of this high-T c superconductor.

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