Charge compensation mechanisms in U 1-x Gd x O 2 and Th 1-x Gd x O 2-x/2 studied by X-ray Absorption Spectroscopy

2017 ◽  
Vol 489 ◽  
pp. 9-21 ◽  
Author(s):  
R. Bès ◽  
J. Pakarinen ◽  
A. Baena ◽  
S. Conradson ◽  
M. Verwerft ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Charge Compensation ◽  
X Ray ◽  
Compensation Mechanisms ◽  
X Ray Absorption ◽  
Th 1

Plutonium and Neptunium Incorporation in Zirconolite

1996 ◽  
Vol 465 ◽  
Author(s):  
B. D. Begg ◽  
E. R. Vance ◽  
R.A Day ◽  
M. Hambley ◽  
S. D. Conradson
Keyword(s):  
Absorption Spectroscopy ◽  
Valence State ◽  
Charge Compensation ◽  
Redox Conditions ◽  
X Ray ◽  
Compensation Mechanisms ◽  
X Ray Absorption

ABSTRACTThe incorporation of Pu and Np in zirconolite (CaZrTi2O7) has been investigated over a range of redox conditions. Zirconolite formulations designed to favour either trivalent or tetravalent Pu and Np were prepared by limiting the amount of charge compensating additives available to maintain electroneutrality. From near-edge X-ray absorption spectroscopy the Pu valence state was found to vary with the processing atmosphere, from completely tetravalent when fired in air, and located on either the Ca or Zr sites, to trivalent, when substituted on the Ca site after annealing in 3.5% H2/N2. Np was predominantly tetravalent over the range of redox conditions examined and was readily incorporated on either of zirconolite's Ca or Zr sites. The charge compensation mechanisms at work in different zirconolites are also discussed.

Charge compensation and capacity fading in LiCoO 2 at high voltage investigated by soft x-ray absorption spectroscopy

2018 ◽  
Vol 27 (10) ◽  
pp. 107802 ◽  
Author(s):  
Xing-Hui Long ◽  
Yan-Ru Wu ◽  
Nian Zhang ◽  
Peng-Fei Yu ◽  
Xue-Fei Feng ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
High Voltage ◽  
Charge Compensation ◽  
Capacity Fading ◽  
X Ray ◽  
X Ray Absorption

The Incorporation of Cerium in Zirconolite

1996 ◽  
Vol 465 ◽  
Author(s):  
B. D. Begg ◽  
E. R. Vance
Keyword(s):  
Absorption Spectroscopy ◽  
Nuclear Waste ◽  
Valence State ◽  
Charge Compensation ◽  
Sample Design ◽  
Sintering Atmosphere ◽  
X Ray ◽  
High Level Nuclear Waste ◽  
High Level ◽  
X Ray Absorption

ABSTRACTZirconolite (CaZrTi2O7) is the primary actinide-bearing Synroc phase for the immobilisation of high-level nuclear waste. Using X-ray absorption spectroscopy and microanalysis we have investigated the incorporation of cerium, as a simulant for plutonium, on both zirconolite's Ca and Zr sites under a range of redox conditions. The Ce valence state was found to vary between Ce3+ and Ce4+ depending on the both the sintering atmosphere and temperature. The existence of alternative charge compensation schemes, predominantly cation vacancies, in addition to those used in the sample design was inferred in many of the zirconolites and will be discussed in detail.

scholarly journals Direct observation of reversible oxygen anion redox reaction in Li-rich manganese oxide, Li2MnO3, studied by soft X-ray absorption spectroscopy

2016 ◽  
Vol 4 (23) ◽  
pp. 9293-9302 ◽  
Author(s):  
Masatsugu Oishi ◽  
Keisuke Yamanaka ◽  
Iwao Watanabe ◽  
Keiji Shimoda ◽  
Toshiyuki Matsunaga ◽  
...  
Keyword(s):  
Manganese Oxide ◽  
Absorption Spectroscopy ◽  
Redox Reaction ◽  
Charge Compensation ◽  
Compensation Mechanism ◽  
Oxygen Anion ◽  
X Ray ◽  
Redox Cycles ◽  
Reversible Redox ◽  
X Ray Absorption

We investigated the reversible charge compensation mechanism of an Li2MnO3 electrode using soft XAS analysis. We concluded that both the Mn and O ions participated in the charge compensation reactions during the reversible redox cycles.

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