The Immobilization of Triuranium Octoxide by Gadolinium Zirconate

2016 ◽  
Vol 193 (3) ◽  
pp. 430-433 ◽  
Author(s):  
Li Liu ◽  
Long Fan ◽  
Xirui Lu
Keyword(s):  
Gadolinium Zirconate ◽  
Triuranium Octoxide

Alpha-Decay Effects in 241Am-Doped Gadolinium Zirconate

2012 ◽  
Vol 1444 ◽  
Author(s):  
S.V. Stefanovsky ◽  
A.G. Ptashkin ◽  
S.V. Yudintsev ◽  
B.F. Myasoedov
Keyword(s):  
Heat Treatment ◽  
Relative Intensity ◽  
Alpha Decay ◽  
Fluorite Structure ◽  
Lattice Parameter ◽  
Oxide Mixture ◽  
Xrd Pattern ◽  
Gadolinium Zirconate ◽  
Main Reflection ◽  
Higher Doses

ABSTRACTSample of zirconate ceramic with a composition corresponding to formula Gd1.7241Am0.3Zr2O7 was synthesized by heat-treatment of mechanically activated and compacted in pellet oxide mixture at 1500 °C for 30 min. The d values on XRD pattern of the sample soon after synthesis (D = 7.9×1015 α-decays/g or 0.001 dpa) demonstrated fluorite structure with the most intensive peak with d111 =3.042 Å (a = 5.269 Å) and very weak diffuse reflections due to d-pyrochlore. At a dose of 7.9×1017 α-decays/g or 0.11 dpa the reflections were broadened by approximately 20% and their relative intensity slightly reduced. At higher doses all the weak superstructure reflections disappeared and the growth in intensity and narrowing of the main reflection occurred. Lattice parameter a increased with the dose and reached 5.343 Å (d111 = 3.085 Å) at a dose of 4.6×1018 α-decays/g or 0.42 dpa. At a dose of 5.5×1018 α-decays/g or 0.78 dpa positions of reflections were shifted to lower d-spaces (d111 value reduced to 3.071 Å) and the half-width of the major reflection was 67% of initial. For the 241Am-doped Gd-zirconate the structure recovery rate exceeds disordering rate and no amorphization occurred at doses higher than ∼0.2-0.3 dpa.

The Kinetics of Ordering in Gadolinium Zirconate: an Unusual Oxygen Ion Conductor

1995 ◽  
Vol 398 ◽  
Author(s):  
Sossina M. Haile ◽  
Scott Meilicke
Keyword(s):  
Impedance Spectroscopy ◽  
Pyrochlore Structure ◽  
Fluorite Structure ◽  
Transformation Kinetics ◽  
X Ray Diffraction ◽  
Ion Conductor ◽  
Gadolinium Zirconate ◽  
X Ray ◽  
Oxygen Ion ◽  
Kinetics Of

ABSTRACTGadolinium zirconate, Gd2Zr2O7, undergoes an order-disorder transition at ∼1550°C, transforming from a defect fluorite structure (Fm3m) to a pyrochlore structure (Fd3m). Both cations and anions are ordered in the low-temperature, pyrochlore structure. In order to understand the interplay between anion and cation order parameters and ordering rates, the transformation kinetics of Gd2Zr2O7 have been examined via X-ray diffraction. Gadolinium zirconate is of particular interest because the oxygen ion conductivity of the ordered phase is significantly greatly than that of the disordered phase, in contrast to virtually every other known solid electrolyte. This difference in conductivity has provided a second technique for characterizing the transformation kinetics: in situ A.C. impedance spectroscopy. Results of the X-ray diffraction showed the growth of superstructure peak intensity to follow an apparent (time)½ dependence, rather than that expected from a nucleation and growth model. The impedance spectroscopy measurements, on the other hand, showed the conductivity to increase linearly with time. These results suggest the transition is second order in nature.

Influence of microstructure on the durability of gadolinium zirconate thermal barrier coatings using APS & SPPS processes

2018 ◽  
Vol 337 ◽  
pp. 117-125 ◽  
Author(s):  
Rishi Kumar ◽  
Drew Cietek ◽  
Chen Jiang ◽  
Jeffrey Roth ◽  
Maurice Gell ◽  
...  
Keyword(s):  
Thermal Barrier Coatings ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Gadolinium Zirconate

Hertzian and Nanoindentations on EBPVD-Coated Gadolinium Zirconate Thermal Barrier Materials

2007 ◽  
pp. 1349-1353
Author(s):  
Kyu Ick Jung ◽  
Sang Hyun Park ◽  
Jong Ho Kim ◽  
Do Kyung Kim ◽  
Un Gyu Paik ◽  
...  
Keyword(s):  
Thermal Barrier ◽  
Gadolinium Zirconate ◽  
Barrier Materials

A Rapid Method for Determining Triuranium Octoxide (U3O8) by Fluorometry

1984 ◽  
Vol 12 (3) ◽  
pp. 177
Author(s):  
R Horstman ◽  
KA Peters ◽  
S Gebremedhin ◽  
RL Meltzer ◽  
MB Vieth ◽  
...  
Keyword(s):  
Rapid Method ◽  
Triuranium Octoxide

Process-Property Relationship for Air Plasma-Sprayed Gadolinium Zirconate Coatings

2014 ◽  
Vol 24 (3) ◽  
pp. 454-466 ◽  
Author(s):  
Gopal Dwivedi ◽  
Yang Tan ◽  
Vaishak Viswanathan ◽  
Sanjay Sampath
Keyword(s):  
Air Plasma ◽  
Gadolinium Zirconate ◽  
Property Relationship ◽  
Process Property ◽  
Plasma Sprayed
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