Study of apical oxygen atoms in a spin-ladder cuprate compound by X-ray absorption spectroscopy near the Cu K edge

1997 ◽  
Vol 251 (1-2) ◽  
pp. 103-106 ◽  
Author(s):  
C.J. Hatterer ◽  
B. Eustache ◽  
L. Collin ◽  
A. Michalowicz ◽  
J. Moscovici ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Spin Ladder ◽  
Apical Oxygen ◽  
X Ray ◽  
X Ray Absorption ◽  
Oxygen Atoms

X-RAY ABSORPTION SPECTROSCOPY IN NaCo2O4, LaCoO3andSrCoO3

2002 ◽  
Vol 09 (02) ◽  
pp. 1327-1331 ◽  
Author(s):  
TOMOHIRA MATSUSHITA ◽  
MASAICHIRO MIZUMAKI ◽  
NAOSHI IKEDA ◽  
MAKOTO NAKAZAWA ◽  
AKANE AGUI ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Absorption Spectroscopy ◽  
Mixed Valence ◽  
Layered System ◽  
X Ray ◽  
Best Fitting ◽  
Ionic States ◽  
X Ray Absorption ◽  
Fitting Parameters ◽  
Oxygen Atoms

We have performed Co 2p X-ray absorption spectroscopy (XAS) on a mixed valence hexagonal layered system NaCo 2 O 4, which shows large thermopower and metallic conductivity. We also measured XAS for SrCoO 3 and LaCoO 3 as examples of typical Co ionic states. The Co ions of the last two materials are octahedrally surrounded by oxygen atoms. A Co atom in NaCo 2 O 4 also has octahedral coordination with oxygen atoms but it is distorted slightly. The Co ions in SrCoO 3 and LaCoO 3 are in the d5 and d6 configuration respectively. The spectrum of NaCo 2 O 4 resembles that of LaCoO 3 rather than that of SrCoO 3; the Co ions in NaCo 2 O 4 can be regarded as the d6 configuration. Also, we have tried to calculate the XAS spectra by using the charge-transfer multiplet model (CT-M). Although we could not find out the best-fitting parameters, the results suggested the itinerancy of the Co 3d states.

XAS STUDY OF (BaCuO2)2/(CaCuO2)n SUPERLATTICES

2000 ◽  
Vol 14 (25n27) ◽  
pp. 2628-2633
Author(s):  
S. COLONNA ◽  
F. ARCIPRETE ◽  
A. BALZAROTTI ◽  
G. BALESTRINO ◽  
P. G. MEDAGLIA ◽  
...  
Keyword(s):  
Fine Structure ◽  
Oxygen Vacancies ◽  
Fluorescence Yield ◽  
Octahedral Coordination ◽  
Apical Oxygen ◽  
Edge Structure ◽  
X Ray ◽  
Local Bonding ◽  
X Ray Absorption ◽  
Oxygen Atoms

EXAFS (Extended X-ray Absorption Fine Structure) and XANES (X-Ray Absorption Near Edge Structure) spectroscopies have been used to probe the local bonding of the artificially layered superconducting (BaCuO2)2/(CaCuO2)n (n = 2, 3, 4) superlattices. Fluorescence-yield measurements have been performed above the Cu and Ba K-edges. This study shows that the charge reservoir (CR) block of the Ba/Ca superlattice contains oxygen vacancies randomly distributed in the CuO2 planes and that the two apical oxygen atoms are displaced out of the Ba plane giving rise to buckled BaO planes. These oxygen atoms have a distorted pyramidal and octahedral coordination around Cu at Ba/Ca interface and in the (BaCuO2) block, respectively.

Characterization of Cerium and Oxygen Atoms in Free Clusters of Cerium Oxide by X-ray Absorption Spectroscopy

2017 ◽  
Vol 61 (1-2) ◽  
pp. 119-125 ◽  
Author(s):  
Tetsuichiro Hayakawa ◽  
Masashi Arakawa ◽  
Shun Sarugaku ◽  
Kota Ando ◽  
Kenichirou Tobita ◽  
...  
Keyword(s):  
Cerium Oxide ◽  
Absorption Spectroscopy ◽  
X Ray ◽  
X Ray Absorption ◽  
Oxygen Atoms

X-RAY ABSORPTION SPECTROSCOPY STUDY OF Cu-BASED METHANOL CATALYSTS. 2. REDUCED STATE

1986 ◽  
Vol 47 (C8) ◽  
pp. C8-237-C8-242 ◽  
Author(s):  
B. S. CLAUSEN ◽  
B. LENGELER ◽  
B. S. RASMUSSEN ◽  
W. NIEMANN ◽  
H. TOPSØE
Keyword(s):  
Absorption Spectroscopy ◽  
Spectroscopy Study ◽  
X Ray ◽  
X Ray Absorption ◽  
Reduced State
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