scholarly journals Engineering of nanoscale defect patterns in CeO2 nanorods via ex situ and in situ annealing

Nanoscale ◽  
2015 ◽  
Vol 7 (12) ◽  
pp. 5169-5177 ◽  
Author(s):  
Tamil Selvan Sakthivel ◽  
David L. Reid ◽  
Umananda M. Bhatta ◽  
Günter Möbus ◽  
Dean C. Sayle ◽  
...  
Keyword(s):  
High Temperature ◽  
Cerium Oxide ◽  
Ex Situ ◽  
Oxide Nanorods ◽  
Oxygen Atoms

Annealing of cerium oxide nanorods results in the evolution of distinct cavities with polyhedral morphologies due to the high temperature activated rearrangement of cerium and oxygen atoms and vacancies on the as-synthesized nanorods.

Grazing Incidence X-Ray Scattering Studies of the Structure and Morphology of the Ni/Mgo(001), Co/Nio(111) and Nife/Nio(111) Interfaces During their in Situ Growth

1999 ◽  
Vol 562 ◽  
Author(s):  
G. Renaud ◽  
A. Barbier ◽  
C. Mocuta
Keyword(s):  
High Temperature ◽  
Magnetic Measurements ◽  
Grazing Incidence ◽  
Ex Situ ◽  
Crystallographic Structure ◽  
Temperature Oxidation ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

ABSTRACTCombined in situ structural and ex situ magnetic studies of the Co/NiO(111) and Ni81Fe19/NiO(111) interfaces are presented. The Co and Permalloy films were grown on NiO(111) single crystals. Structural studies were performed by Grazing Incidence X-ray Scattering during growth. The effect of the temperature of the substrate during deposition was investigated. Under specific growth conditions, almost pure FCC Co and NiFe films can be obtained, with small quantities of twins. Magnetic measurements were performed ex situ by Magneto-Optical Kerr Effect (MOKE). A strong correlation between the magnetic properties and the crystallographic structure of the Co film is evidenced. High coercive fields are measured for all samples. High temperature annealing of the NiFe film leads to an improved crystalline quality, but the interface becomes reactive and diffuse: part of the Fe diffuses into the NiO substrate and forms an interface compound, likely to be the spinel NiFe2O4. We also report an in situ grazing incidence X-ray scattering study of the Ni/MgO(001) interface during its formation at room temperature. In-plane measurements reveal that the interface is sharp and that the epitaxial relationship is complex. Two distinct lattices are found to exist: expanded Ni(001) and Ni(110). The latter exhibits several orientations with respect to the substrate depending on the thickness. The Ni(110) orientations disappear by annealing at high temperature, leaving only the Ni cube/cube orientation. The layer was also almost fully transformed into NiO(001) by high temperature oxidation.

High Temperature - FTIR Characterization of Gadolinia Doped Ceria

2010 ◽  
Vol 72 ◽  
pp. 249-254
Author(s):  
Aliye Arabaci ◽  
Nuri Solak
Keyword(s):  
High Temperature ◽  
Thermal Analyses ◽  
Water Soluble ◽  
Ex Situ ◽  
Doped Ceria ◽  
X Ray Diffraction ◽  
Ftir Characterization ◽  
Ft Ir ◽  
Xrd Techniques

Doped ceria-based (DC) materials have recently been considered as the most promising solid electrolytes for intermediate temperature solid oxide fuel cell (IT-SOFC) applications. Doped ceria is usually prepared via thermal decomposition of its water soluble salts, especially, acetates and nitrates. The properties of the obtained final product directly influenced by the starting material and the decomposition products. Therefore, it is crucial to understand the decomposition steps and intermediate products. Number of experimental work have been reported using various <em>in-situ</em> and <em>ex-situ</em> techniques such as thermogravimetry with mass spectrometry (TG/DTA-MS), X-ray diffraction with differential scanning calorimeter (XRD-DSC). However, the available literature data is limited and not reasonably in agreement with each other. High Temperature FT-IR spectroscopy, TG/DTA-MS, XRD, techniques were used and results are compared with literature. A good agreement between the thermal analyses and HT-FTIR results were obtained. Possible decomposition mechanism is discussed.

In situ and ex situ characterisation of oxide films formed on strained stainless steel surfaces in high-temperature water

2006 ◽  
Vol 252 (24) ◽  
pp. 8580-8588 ◽  
Author(s):  
Yoichi Takeda ◽  
Tetsuo Shoji ◽  
Martin Bojinov ◽  
Petri Kinnunen ◽  
Timo Saario
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Oxide Films ◽  
Ex Situ ◽  
High Temperature Water ◽  
Steel Surfaces ◽  
Temperature Water

High-temperature oxidation of CoGa: Influence of the crystallographic orientation on the oxidation rate

2002 ◽  
Vol 17 (10) ◽  
pp. 2489-2498 ◽  
Author(s):  
U. Koops ◽  
D. Hesse ◽  
M. Martin
Keyword(s):  
High Temperature ◽  
Crystallographic Orientation ◽  
High Temperature Oxidation ◽  
Elevated Temperatures ◽  
Electron Backscatter Diffraction ◽  
Ex Situ ◽  
Temperature Oxidation ◽  
Transmission Electron ◽  
Backscatter Diffraction

The crystallographic orientation plays an important role in high-temperature oxidation of the intermetallic compound CoGa. When CoGa is exposed to air at elevated temperatures, the oxide β–Ga2O3 is formed, and different scale growth rates are observed, depending on the crystallographic orientation of the CoGa grains. This dependence is a consequence of the anisotropy of the gallium diffusion rate through the β–Ga2O3 scale and of a topotaxial orientation relationship occurring between β–Ga2O3 and CoGa. The combination of ex situ techniques, such as transmission electron microscopy and electron backscatter diffraction with optical microscopy, applied in situ resulted in a thorough understanding of these relations and of the oxidation process in general.

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