Isothermal nucleation and growth kinetics of Pd/Ag alloy phase via in situ time-resolved high-temperature X-ray diffraction (HTXRD) analysis

By 3 dimensional X-ray diffraction (3DXRD) using high energy X-rays from synchrotron sources it is possible to study in-situ the nucleation and growth during recrystallization. In this paper it is described and discussed how 3DXRD can supplement EBSP measurements of nucleation and growth. Three types of studies are considered: i) orientation relationships between nuclei and parent deformed matrix, ii) recrystallization kinetics of individual bulk grains and iii) filming of growing grains in deformed single crystals.

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

Journal of Materials Research ◽

10.1557/jmr.1994.0275 ◽

1994 ◽

Vol 9 (2) ◽

pp. 275-285 ◽

Cited By ~ 19

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.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.558-559.943 ◽

2007 ◽

Vol 558-559 ◽

pp. 943-947 ◽

Cited By ~ 1

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.

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