Influence of oxygen partial pressure on the kinetics of YBa2Cu3O7−x formation

1994 ◽  
Vol 9 (2) ◽  
pp. 275-285 ◽  
Author(s):  
V. Milonopoulou ◽  
K.M. Forster ◽  
J.P. Formica ◽  
J. Kulik ◽  
J.T. Richardson ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
Decomposition Products ◽  
Time Resolved ◽  
X Ray ◽  
Formation Kinetics ◽  
Dimensional Diffusion ◽  
Diffusion Controlled ◽  
Gas Atmosphere ◽  
Kinetics Of

The YBa2Cu3O7−x formation kinetics from a spray-roasted precursor powder containing Y2O3, BaCO3, and CuO was followed via in situ, time-resolved x-ray diffraction as a function of gas atmosphere and temperature. In inert atmospheres, BaCO3 and CuO form BaCu2O2 which subsequently reacts with Y2O3 to form YBa2Cu3O6. However, YBa2Cu3O6 decomposes at temperatures exceeding 725 °C with Y2BaCuO5 being one of the decomposition products. In oxidizing atmospheres, YBa2Cu3O7−x formation involves the BaCuO2. At high temperatures (800–840 °C), oxygen increases the yield of YBa2Cu3O6. A nuclei growth model assuming two-dimensional, diffusion-controlled growth with second-order nucleation rate fits the experimental data.

Kinetics of Multi-Step Redox Processes by Time-Resolved In Situ X-ray Diffraction

2016 ◽  
Vol 88 (11) ◽  
pp. 1684-1692 ◽  
Author(s):  
Lukas C. Buelens ◽  
Vladimir V. Galvita ◽  
Hilde Poelman ◽  
Christophe Detavernier ◽  
Guy B. Marin
Keyword(s):  
Redox Processes ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Kinetics Of

In Situ Time-Resolved X-Ray Diffraction Investigation of the ω→ψ Transition in Al-Cu-Fe Quasicrystal-Forming Alloys

2007 ◽  
Vol 558-559 ◽  
pp. 943-947 ◽  
Author(s):  
E. Otterstein ◽  
R. Nicula ◽  
J. Bednarčík ◽  
M. Stir ◽  
E. Burkel
Keyword(s):  
Large Scale ◽  
Applied Pressure ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
In Situ Xrd ◽  
Kinetics Of

Quasicrystals are aperiodic long-range ordered solids with a high potential for many modern applications. Interest is nowadays paid to the development of economically viable large-scale synthesis procedures of quasicrystalline materials involving solid-state transformations. The kinetics of the high-temperature phase transition from the complex ω-phase to the icosahedral quasicrystalline (iQC) ψ-phase in AlCuFe nanopowders was here examined by in-situ time-resolved X-ray diffraction experiments using synchrotron radiation. In-situ XRD experiments will allow insight on the influence of uniaxial applied pressure on the kinetics of phase transitions leading to the formation of single-phase QC nanopowders and further contribute to the optimization of sintering procedures for nano-quasicrystalline AlCuFe alloy powders.

In situ investigation of the selenization kinetics of Cu–Ga precursors using time-resolved high-temperature X-ray diffraction

2007 ◽  
Vol 515 (15) ◽  
pp. 5837-5842 ◽  
Author(s):  
W.K. Kim ◽  
E.A. Payzant ◽  
T.J. Anderson ◽  
O.D. Crisalle
Keyword(s):  
High Temperature ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
In Situ Investigation ◽  
Kinetics Of

Calcite nucleation on the surface of PNIPAM–PAAc micelles studied by time resolved in situ PXRD

CrystEngComm ◽  
2015 ◽  
Vol 17 (36) ◽  
pp. 6940-6946 ◽  
Author(s):  
Anders C. S. Jensen ◽  
Mogens Hinge ◽  
Henrik Birkedal
Keyword(s):  
Block Copolymers ◽  
Acrylic Acid ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Formation Kinetics ◽  
Nanocrystal Formation ◽  
Poly Acrylic Acid

Nanocrystalline calcite is formed under the influence of block copolymers containing thermoresponsive PNIPAM and a mineralization controlling block of poly(acrylic acid) and the nanocrystal formation kinetics studied by in situ X-ray diffraction.

Time Resolved X-Ray Diffraction Study of the Transformation Kinetics of TiSi2-C49 in Amorphous Si/Ti Multilayers

1993 ◽  
Vol 311 ◽  
Author(s):  
J. Sariel ◽  
Haydn Chen ◽  
J. F. Jongste ◽  
S. Radelaar
Keyword(s):  
Type Equation ◽  
Reaction Rate Constant ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Formation Kinetics ◽  
Device Processing ◽  
Measured Activation ◽  
Amorphous Si ◽  
Kinetics Of

ABSTRACTAmorphous Si/Ti multilayers transform at high temperatures (above 700°C) to TiSi2-C54. This phase is important for microelectronics applications because of its low resistivity, stability up to 900°C, and compatibility with silicon processing. However, an unfavorable metastable TiSi2-C49 phase is usually formed at lower temperatures. Thus, an understanding of the C49 phase formation kinetics is useful to the device processing strategy. The kinetics of the transformation of TiSi2-C49 phase can be characterized as a process of nucleation and growth, using the well known Johnson Mehl Avrami (JMA) equation. In the present work the formation kinetics of the C49 phase has been studied by an in situ x-ray diffraction technique. Isothermal annealing in vacuum was done at four temperatures, in the range of 275"C to 310°C. A position sensitive detector (PSD) was used to simultaneously collect the diffracted beams of (131) and (150) peaks of the C49 phase. From the data, the Avrami exponent, n, was determined to be 2.0±0.1. The reaction rate constant k follows a familiar Arrhenius-type equation with a measured activation energy of 2.5eV. Comparison of our x-ray results with kinetic data obtained by other means will be discussed.

Structural Evolution of Amorphous Ge2Sb2Te5 Thin Films in the Transition to the Crystalline Phase

2008 ◽  
Vol 1072 ◽  
Author(s):  
Riccardo De Bastiani ◽  
Alberto Maria Piro ◽  
Maria Grazia Grimaldi ◽  
Emanuele Rimini ◽  
Giuseppe Baratta ◽  
...  
Keyword(s):  
Thin Films ◽  
Crystalline Phase ◽  
Short Range ◽  
Structural Modification ◽  
Structural Evolution ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Kinetics Of

ABSTRACTThe crystallization kinetics of as-deposited amorphous Ge2Sb2Te5 thin films has been measured by in situ time resolved reflectivity. X-ray diffraction and Raman scattering analyses of partially transformed samples allowed to correlate the evolution of the transition to the structural modification in the long and short range configuration. The experimental results evidenced that during the early stages of crystallization there is a reduction of Ge-Te tetrahedral bonds, characteristics of the Ge coordination in amorphous Ge2Sb2Te5 films.

Dehydrogenation kinetics of pure and nickel-doped magnesium hydride investigated by in situ time-resolved powder X-ray diffraction

2006 ◽  
Vol 31 (14) ◽  
pp. 2052-2062 ◽  
Author(s):  
T JENSEN ◽  
A ANDREASEN ◽  
T VEGGE ◽  
J ANDREASEN ◽  
K STAHL ◽  
...  
Keyword(s):  
Magnesium Hydride ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Dehydrogenation Kinetics ◽  
Kinetics Of

Determination of the kinetics of crystallisation of gibbsite using time resolved in situ energy dispersive powder X-ray diffraction

2000 ◽  
Vol 10 (10) ◽  
pp. 2355-2357 ◽  
Author(s):  
Andrew M. Fogg ◽  
Stephen J. Price ◽  
Robin J. Francis ◽  
Stephen O'Brien ◽  
Dermot O'Hare
Keyword(s):  
Energy Dispersive ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Kinetics Of
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