Determination of valence state of Mn ions in Pr1−xAxMnO3−δ (A=Ca, Sr) by Mn-L3 X-ray absorption near-edge structure analysis

2012 ◽  
Vol 185 (5-7) ◽  
pp. 129-132 ◽  
Author(s):  
Haruto Kanamori ◽  
Tsuyoshi Yoshioka ◽  
Kazuyuki Hirose ◽  
Tomoyuki Yamamoto
2011 ◽  
Vol 99 (26) ◽  
pp. 262105 ◽  
Author(s):  
Justus Just ◽  
Dirk Lützenkirchen-Hecht ◽  
Ronald Frahm ◽  
Susan Schorr ◽  
Thomas Unold

ACS Omega ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 14981-14985 ◽  
Author(s):  
Rui Yang ◽  
David J. Morris ◽  
Tatsuya Higaki ◽  
Matthew J. Ward ◽  
Rongchao Jin ◽  
...  

2020 ◽  
Vol 109 (6) ◽  
pp. 2095-2099
Author(s):  
Masataka Ito ◽  
Rika Shiba ◽  
Hironori Suzuki ◽  
Shuji Noguchi

2012 ◽  
Vol 1480 ◽  
Author(s):  
Christina M. Gonzalez ◽  
Jason G. Parsons ◽  
Jeffrey Hernandez ◽  
Jorge L. Gardea-Torresdey

ABSTRACTIncreasing concentrations of selenium oxoanions in the environment are placing many animals at risk for reproduction failure and deformities. The understanding of binding mechanisms of selenium oxoanions to iron and manganese based oxide minerals could lead to enhanced understanding of selenium mobility in the environment. In this study, the binding mechanisms of selenium oxoanions, selenite and selenate, to non microwave-assisted and microwave-assisted synthetic Fe3O4, Mn3O4, and MnFe2O4 nanomaterials were investigated through the use of X-ray absorption spectroscopy. The X-ray absorption near-edge structure (XANES) spectroscopy studies revealed the oxidation state of selenite and selenate remains the same after binding occurs to all nanomaterials in pH 2, 4, or 6 environments. The binding modes of selenite and selenate were determined to be bidentate binuclear through use of Extended x-ray absorption fine structure (EXAFS) and were independent of nanomaterials, synthetic technique, and pH.


2011 ◽  
Vol 18 (2) ◽  
pp. 238-244 ◽  
Author(s):  
Florian Meirer ◽  
Bernhard Pemmer ◽  
Giancarlo Pepponi ◽  
Norbert Zoeger ◽  
Peter Wobrauschek ◽  
...  

2014 ◽  
Vol 21 (04) ◽  
pp. 1450058 ◽  
Author(s):  
WEI CAO ◽  
VLADIMIR PANKRATOV ◽  
MARKO HUTTULA ◽  
LIANA SHIRMANE ◽  
YU RAN NIU ◽  
...  

In this paper, we reported on the X-ray photoemission electron microscope (XPEEM) determination of magnetic and luminescence origins for two Co x Zn 1-x O films. The cobalt fraction x of radio frequency co-sputtered samples were 0.86(2) and 0.92(2), respectively. Films were ferromagnetic and semiconductive. Unique narrow green color lines beside the ZnO intrinsic emissions were found with a decay time in microsecond range at room temperature. Origins of magnetic and luminescence properties were determined with XPEEM. The X-ray absorption near edge structure at the Co  L3-edge denoted that Co was partially oxidized, and phase-contrast images together with chemical composition identification further proved that Co and CoO co-existed in the samples. The ferromagnetism was attributed to ferromagnetism of Co clusters partially canceled by the antiferromagnetism of its oxide, and the photoluminescence to bound exciton in ZnO nanoclusters and defect related centers of ZnO nanoclusters in a Co -rich matrix. Present results show possibilities for adjusting magnetic and luminescence properties of Co – ZnO compounds by changing the cobalt concentration.


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