Nickel oxide–zirconium oxide: Ni2+incorporation and its influence on the phase transition and sintering of zirconia

1995 ◽  
Vol 5 (1) ◽  
pp. 183-189 ◽  
Author(s):  
Mario Valigi ◽  
Delia Gazzoli ◽  
Roberto Dragone ◽  
Monica Gherardi ◽  
Giuliano Minelli
Keyword(s):  
Phase Transition ◽  
Nickel Oxide ◽  
Zirconium Oxide

Zirconium oxide nanoarrays via the self-organized anodizing of Al/Zr bilayers on substrates

2021 ◽  
Author(s):  
Alexander Mozalev ◽  
Zdenek Pytlicek ◽  
Kirill Kamnev ◽  
Jan Prasek ◽  
Francesc Gispert-Guirado ◽  
...  
Keyword(s):  
Phase Transition ◽  
Zirconium Oxide ◽  
Ionic Transport ◽  
The Self ◽  
Oxide Growth ◽  
Frontier Formation ◽  
Self Organized ◽  
Oxide Nanostructures ◽  
Formation Conditions ◽  
Transition Effects

A combination of frontier formation conditions, paradoxical oxide growth, unique ionic transport, a mixed-oxide composition, and phase transition effects resulted in arrays of novel self-assembled zirconium-oxide nanostructures.

Magnetic Phase Transition in Nickel Oxide

2015 ◽  
Vol 2 (10) ◽  
pp. 5262-5267 ◽  
Author(s):  
Shahid Atiq ◽  
Muhammad Javid ◽  
Saira Riaz ◽  
Shahzad Naseem
Keyword(s):  
Phase Transition ◽  
Nickel Oxide ◽  
Magnetic Phase Transition ◽  
Magnetic Phase

FABRICATION OF ZIRCONIUM OXIDE NANOCRYSTALLITES AND THE CRITICAL SIZE OF THE PHASE TRANSITION

2006 ◽  
Vol 05 (04n05) ◽  
pp. 651-656 ◽  
Author(s):  
SHIN TSUNEKAWA ◽  
YOSHIYUKI KAWAZOE ◽  
TAKASHI KOJIMA ◽  
TADAO SUGIMOTO
Keyword(s):  
Phase Transition ◽  
Photoelectron Spectroscopy ◽  
Zirconium Oxide ◽  
Size Range ◽  
Critical Size ◽  
Thermal Hydrolysis ◽  
X Ray ◽  
Organic Complexes ◽  
Nanocrystalline Particles ◽  
Pure Zirconium

Pure zirconium oxide nanocrystalline particles of the size range 6–140 nm in diameter are fabricated from ultrafine metallo-organic complexes by thermal hydrolysis at 120°C and heat treatment at 125 to 1025°C. X-ray powder diffraction for nearly monodispersed nanocrystallites reveals that the critical size of the ferroelastic transition between the tetragonal and monoclinic phases is around 25 nm in diameter. The critical size from the cubic to the tetragonal is strongly suggested to be 5 nm in diameter by X-ray photoelectron spectroscopy.

scholarly journals THE EFFECTS OF DIFFERENT SONICATION TIMES OF NICKEL OXIDE AND ZIRCONIUM OXIDE CATALYSTS IN SYNGAS PRODUCTION

2018 ◽  
Vol 80 (6) ◽  
Author(s):  
Y. C. Wong ◽  
W. A. Wan Nurdiyana ◽  
Y. H. Taufiq Yap
Keyword(s):  
Electron Microscopy ◽  
Nickel Oxide ◽  
Surface Area ◽  
Zirconium Oxide ◽  
Treatment Duration ◽  
Reactive Oxygen ◽  
Oxygen Removal ◽  
Surface Measurement ◽  
Heterogeneous Catalytic ◽  
Syngas Production

Heterogeneous catalytic cracking is currently one of the most effective ways for both reducing tar content and enhancing hydrogen (H2) content in syngas at relatively low temperature, besides being environmental friendly. Sonochemical treatment has also been shown to lower reaction times with enhanced reaction rate and enables production of particles with high surface area. In this study, two different types of metal oxides, which are Nickel oxide (NiO) and Zirconium oxide (ZrO2) at a combination of 1:1 ratio with Zeolite as the supporter are synthesized via sonochemical treatment in durations of 30, 60 and 90 minutes. The catalysts are then characterized using X-Ray Diffraction (XRD), Temperature Programmed Reduction (TPR-H2), Brunauer-Emmett-Teller surface measurement (BET), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). From SEM and TEM analysis, Nickel tends to agglomerate and form sizable globular shapes, Zirconium forms coral-like branching structure and Zeolite forms stacks of cubic clumps. The most promising sonication treatment duration for the catalysts is 30 minutes because it removes decent amount of reactive oxygen at a rate of 0.83 x 1021 atoms/g during hydrogen reduction, possesses the highest surface area of 506.52 m2/g as well as smallest average crystallite size of 56.9 nm compared to other durations. Generally sonochemical treatment also increases the catalysts surface area and oxygen removal as well as lowers the reduction temperature which is favourable in term of production cost. Catalysts with sonochemical treatment duration of 30 and 60 minutes generally show higher reactive oxygen removal and surface area compared to catalysts with 90 minute treatments.

scholarly journals Oxidation Mechanism of Nickel Oxide/Carbon Nanotube Composite

2013 ◽  
Vol 19 (S5) ◽  
pp. 202-206 ◽  
Author(s):  
Tae-Hoon Kim ◽  
Min-Ho Park ◽  
Jiho Ryu ◽  
Cheol-Woong Yang
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Thermal Stability ◽  
Carbon Nanotube ◽  
Nickel Oxide ◽  
Oxidation Mechanism ◽  
Transmission Electron ◽  
Carbon Nanotube Composite ◽  
Thermal Stability Of

AbstractThe oxidation mechanism and thermal stability of nickel oxide (NiO)/carbon nanotube (CNT) composites were investigated by examining composites with different NiO contents by thermogravimetric analysis and transmission electron microscopy (TEM). NiO acts as a catalyst in the oxidation of CNT in the composite. CNTs can be oxidized, even in a vacuum, by reducing NiO to nickel at temperatures lower than the normal oxidation temperature of CNTs. This phase transition was confirmed directly by in situ heating TEM observations. In air, reduction by CNT occurs simultaneously with reoxidation by gaseous O2 molecules, and NiO maintains its phase. The thermal stability decreased with increasing NiO content because of defects in the CNT generated by the NiO loading.

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