Mn K-Edge X-Ray Absorption Spectroscopy (XAS) Studies of La1-xSrxMnO3

1997 ◽  
Vol 494 ◽  
Author(s):  
S. M. Mini ◽  
J. F. Mitchells ◽  
D. G. Hinks ◽  
Ahmet Alatasi ◽  
D. Rosenmann ◽  
...  
Keyword(s):  
Manganese Oxide ◽  
Absorption Spectroscopy ◽  
Energy Shift ◽  
Hole Doping ◽  
Oxide Systems ◽  
X Ray ◽  
Colossal Magnetoresistive ◽  
The Difference ◽  
X Ray Absorption ◽  
Made In

ABSTRACTSystematic Mn K-edge x-ray absorption spectroscopy (XAS) measurements on samples of La1-xSrxMnO3, which are precursors to colossal magnetoresistive (CMR) materials, are reported. Detailed results on the edge or chemical shift as a function of Sr concentration (hole doping) and sample preparation (air vs oxygen annealed), are discussed. For comparison, a systematic XANES study of the Mn K-edge energy shift, denoting valence change in Mn, has been made in standard manganese oxide systems. Contrary to expectations, the variation in near-edge energies for Mn in La0.725Sr0.275MnO3 were small when compared to the difference between that for manganese oxide standards of nominal valence of +3 and +4 (Mn2O3 and MnO2).

scholarly journals Arsenite Oxidation by a Poorly Crystalline Manganese-Oxide. 2. Results from X-ray Absorption Spectroscopy and X-ray Diffraction

2010 ◽  
Vol 44 (22) ◽  
pp. 8467-8472 ◽  
Author(s):  
Brandon J. Lafferty ◽  
Matthew Ginder-Vogel ◽  
Mengqiang Zhu ◽  
Kenneth J. T. Livi ◽  
Donald L. Sparks
Keyword(s):  
Manganese Oxide ◽  
Absorption Spectroscopy ◽  
X Ray Diffraction ◽  
Arsenite Oxidation ◽  
X Ray ◽  
X Ray Absorption

scholarly journals NO binding kinetics in myoglobin investigated by picosecond Fe K-edge absorption spectroscopy

2015 ◽  
Vol 112 (42) ◽  
pp. 12922-12927 ◽  
Author(s):  
Mahsa Silatani ◽  
Frederico A. Lima ◽  
Thomas J. Penfold ◽  
Jochen Rittmann ◽  
Marco E. Reinhard ◽  
...  
Keyword(s):  
Active Center ◽  
Absorption Spectroscopy ◽  
Spectroscopic Studies ◽  
Pump Probe ◽  
X Ray ◽  
The Difference ◽  
Direct Sensitivity ◽  
X Ray Absorption ◽  
Recombination Kinetics ◽  
532 Nm

Diatomic ligands in hemoproteins and the way they bind to the active center are central to the protein’s function. Using picosecond Fe K-edge X-ray absorption spectroscopy, we probe the NO-heme recombination kinetics with direct sensitivity to the Fe-NO binding after 532-nm photoexcitation of nitrosylmyoglobin (MbNO) in physiological solutions. The transients at 70 and 300 ps are identical, but they deviate from the difference between the static spectra of deoxymyoglobin and MbNO, showing the formation of an intermediate species. We propose the latter to be a six-coordinated domed species that is populated on a timescale of ∼200 ps by recombination with NO ligands. This work shows the feasibility of ultrafast pump–probe X-ray spectroscopic studies of proteins in physiological media, delivering insight into the electronic and geometric structure of the active center.

scholarly journals Redox Processes of Manganese Oxide in Catalyzing Oxygen Evolution and Reduction: An in Situ Soft X-ray Absorption Spectroscopy Study

2017 ◽  
Vol 121 (33) ◽  
pp. 17682-17692 ◽  
Author(s):  
Marcel Risch ◽  
Kelsey A. Stoerzinger ◽  
Binghong Han ◽  
Tom Z. Regier ◽  
Derek Peak ◽  
...  
Keyword(s):  
Manganese Oxide ◽  
Oxygen Evolution ◽  
Absorption Spectroscopy ◽  
Redox Processes ◽  
Spectroscopy Study ◽  
X Ray ◽  
X Ray Absorption

Electron- and Hole-Doping Effects in Manganites Studied by X-Ray Absorption Spectroscopy

2005 ◽  
Vol 160 (1-4) ◽  
pp. 181-187 ◽  
Author(s):  
K. Asokan ◽  
J. C. Jan ◽  
K. V. R. Rao ◽  
J. W. Chiou ◽  
H. M. Tsai ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Hole Doping ◽  
X Ray ◽  
Doping Effects ◽  
X Ray Absorption

Characterization of Ce-Doped LaPO4 by X-Ray Absorption Spectroscopy

1993 ◽  
Vol 329 ◽  
Author(s):  
D. K. Shuh ◽  
L. J. Terminello ◽  
L. A. Boatner ◽  
M. M. Abraham ◽  
D. Perry
Keyword(s):  
Absorption Spectroscopy ◽  
Full Width Half Maximum ◽  
Energy Shift ◽  
Total Electron Yield ◽  
Total Electron ◽  
X Ray ◽  
Trivalent State ◽  
Radiation Laboratory ◽  
X Ray Absorption

AbstractX-ray Absorption Spectroscopy (XAS) of the Rare Earth (RE) 3d levels yields sharp peaks near the edges as a result of strong, quasi-atomic 3d104fn→3d94fn+1 (M4,5) transitions that contain a wealth of spectroscopic features. XAS is a useful technique for the characterization of 4f-occupancy, 4f-hybridization, and valence in RE-containing materials. The XAS measurements of the single crystal RE-orthophosphates, as well as a range of Ce- doped (˜l–30%) LaPO4 hosts were performed at the 3d edge in the total electron yield mode at beamline 8–2 at the Stanford Synchrotron Radiation Laboratory (SSRL). The XAS spectra of the RE ions in the orthophosphate matrix generally resemble that of the corresponding RE metal and emphasize the major contribution of the trivalent state to the electronic transitions occurring at the 3d edge. There is no energy shift of the La and Ce absorption peaks with Ce doping and furthermore, no additional transitions are observed in either spectral region. However, accompanying the Ce doping there is a significant narrowing of the La absorption peak full width half maximum that contrasts to the Ce features that exhibit no contraction. The La and Ce spectra indicate that the Ce-doping of LaPO4 is purely substitutional.

scholarly journals Temperature-dependent x-ray absorption spectroscopy of colossal magnetoresistive perovskites

2005 ◽  
Vol 71 (12) ◽  
Author(s):  
N. Mannella ◽  
A. Rosenhahn ◽  
M. Watanabe ◽  
B. Sell ◽  
A. Nambu ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Temperature Dependent ◽  
X Ray ◽  
Colossal Magnetoresistive ◽  
X Ray Absorption
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