In situ x-ray diffraction studies on epitaxial VO2 films grown on c-Al2O3 during thermally induced insulator-metal transition

2010 ◽  
Vol 107 (6) ◽  
pp. 063503 ◽  
Author(s):  
Kunio Okimura ◽  
Joe Sakai ◽  
Shriram Ramanathan
Keyword(s):  
X Ray Diffraction ◽  
Thermally Induced ◽  
X Ray ◽  
Insulator Metal Transition

Probing the isothermal δ→α' martensitic transformation in Pu-Ga with in situ x-ray diffraction

2010 ◽  
Vol 1264 ◽  
Author(s):  
Jason R. Jeffries ◽  
Kerri J.M. Blobaum ◽  
Adam J. Schwartz ◽  
Hyunchae Cynn ◽  
Wenge Yang ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Intermediate Phase ◽  
X Ray Diffraction ◽  
Thermally Induced ◽  
X Ray ◽  
Conditioning Treatment ◽  
Temperature Transformation ◽  
Isothermal Martensitic Transformation ◽  
Photon Source

AbstractThe time-temperature-transformation (TTT) curve for the δ → α′ isothermal martensitic transformation in a Pu-1.9 at. % Ga alloy exhibits an anomalous double-C curve. Recent work suggests that an ambient temperature conditioning treatment enables the lower-C curve. However, the mechanisms responsible for the double-C are still not fully understood. When the δ → α′ transformation is induced by pressure, an intermediate γ′ phase is observed in some alloys. It has been suggested that transformation at upper-C temperatures may proceed via this intermediate phase, while lower-C transformation progresses directly from δ to α′. To investigate the possibility of thermally induced transformation via the intermediate γ′ phase, in situ x-ray diffraction at the Advanced Photon Source was performed. Using transmission x-ray diffraction, the δ → α′ transformation was observed as a function of time and temperature in samples as thin as 30 μm. The intermediate γ′ phase was not observed at -120°C (upper-C curve) or -155 °C (lower-C curve). Results indicate that the bulk of the α′ phase forms relatively rapidly at -120 and -155 °C.

Probing Thermally Induced Decomposition of Delithiated Li1.2–xNi0.15Mn0.55Co0.1O2 by in Situ High-Energy X-ray Diffraction

2014 ◽  
Vol 6 (15) ◽  
pp. 12692-12697 ◽  
Author(s):  
Chi-kai Lin ◽  
Ying Piao ◽  
Yongchun Kan ◽  
Javier Bareño ◽  
Ira Bloom ◽  
...  
Keyword(s):  
High Energy ◽  
X Ray Diffraction ◽  
Thermally Induced ◽  
X Ray ◽  
Induced Decomposition

Thermally induced transformations of Au@Cu2O core–shell nanoparticles into Au–Cu nanoparticles from temperature-programmed in situ powder X-ray diffraction

2019 ◽  
Vol 52 (3) ◽  
pp. 579-586 ◽  
Author(s):  
Robert Koch ◽  
Guangfang Li ◽  
Shubham Pandey ◽  
Simon Phillpot ◽  
Hui Wang ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
Thermally Induced ◽  
X Ray ◽  
Cu Content ◽  
Temperature Programmed ◽  
Core Shell Nanoparticles

Temperature-programmed in situ X-ray diffraction with whole-powder-pattern modeling is used to investigate the reaction of Au@Cu2O core–shell nanoparticles to form nanocrystalline bimetallic Cu x Au1−x alloys (x = 0, 0.25, 0.5, 0.75, 1.0) in a reducing atmosphere. The mechanisms of the reactions are key to informed design of tailored non-equilibrium nanostructures for catalytic and plasmonic materials. The Au@Cu2O reaction is initiated by reduction of the Cu2O cuprite shell to form nanocrystalline metallic Cu at about 413 K. Alloying begins immediately upon formation of metallic Cu at 413 K, with the nucleation of an Au-rich alloy phase which reaches the nominal Cu content of the overall system stoichiometry by 493 K. All bimetallic alloys form a transient ordered Cu3Au intermetallic compound at intermediate temperatures, with the onset of ordering and subsequent disordering varying by composition. No evidence for an ordered Au3Cu intermetallic is found for any composition. Significant crystal growth in the bimetallic phase is apparent at higher temperatures, with the onset temperature increasing with Cu concentration and initial Cu-shell thickness. The reduction of the cuprite phase is slowed by the presence of the core–shell interface, and crystal growth in the Cu shell is completely suppressed within the alloy systems.

Observation of Lattice Plane Bending during SiC PVT Bulk Growth Using In Situ High Energy X-Ray Diffraction

2010 ◽  
Vol 645-648 ◽  
pp. 29-32 ◽  
Author(s):  
Rainer Hock ◽  
Katja Konias ◽  
L. Perdicaro ◽  
Andreas Magerl ◽  
Philip Hens ◽  
...  
Keyword(s):  
Growth Process ◽  
Growth Front ◽  
High Energy ◽  
Lattice Plane ◽  
X Ray Diffraction ◽  
Thermally Induced ◽  
X Ray ◽  
Bulk Growth ◽  
Plane Bending

We have investigated thermally induced strain in the SiC crystal lattice during physical vapor transport bulk growth. Using high energy x-ray diffraction lattice plane bending was observed in-situ during growth. With increasing growth rate increasing lattice plane bending and, hence, strain was observed. A comparison with numerical modeling of the growth process shows that the latter is related to the heat of crystallization which needs to be dissipated from the crystal growth front. The related temperature gradient as driving force for the dissipation of the heat of crystallization causes lattice plane bending. Optimization of the growth process needs to consider such effects.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

In-situ Investigation of Bainite Formation with fast X-Ray Diffraction (iXRD)

2017 ◽  
Vol 72 (6) ◽  
pp. 355-364
Author(s):  
A. Kopp ◽  
T. Bernthaler ◽  
D. Schmid ◽  
G. Ketzer-Raichle ◽  
G. Schneider
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Investigation

Texture Evolution Under Fast Heating and Cooling Rates of Zirconium Alloys Studied In-Situ by Synchrotron X-Ray Diffraction

2020 ◽  
Author(s):  
Chi-Toan Nguyen ◽  
Alistair Garner ◽  
Javier Romero ◽  
Antoine Ambard ◽  
Michael Preuss ◽  
...  
Keyword(s):  
Texture Evolution ◽  
Zirconium Alloys ◽  
X Ray Diffraction ◽  
Fast Heating ◽  
Cooling Rates ◽  
X Ray ◽  
Heating And Cooling
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