High temperature structure of BaBiO3 by single-crystal neutron diffraction

1991 ◽  
Vol 185-189 ◽  
pp. 2723-2724 ◽  
Author(s):  
C. Chaillout ◽  
J. Marcus ◽  
M. Marezio
Keyword(s):  
High Temperature ◽  
Neutron Diffraction ◽  
Single Crystal ◽  
Temperature Structure ◽  
High Temperature Structure

The role of π-bonding on the high temperature structure of the double perovskites Ba2CaUO6and BaSrCaUO6

2015 ◽  
Vol 44 (36) ◽  
pp. 16036-16044 ◽  
Author(s):  
Emily Reynolds ◽  
Gordon J. Thorogood ◽  
Maxim Avdeev ◽  
Helen E. A. Brand ◽  
Qinfen Gu ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Neutron Diffraction ◽  
Temperature Structure ◽  
Double Perovskites ◽  
Phase Transition Behavior ◽  
X Ray ◽  
Progressive Loss ◽  
Octahedral Tilting

High temperature synchrotron X-ray and neutron diffraction powder diffraction studies of the uranium perovskites Ba2CaUO6and BaSrCaUO6reveal unusual phase transition behavior associated with the progressive loss of cooperative octahedral tilting.

Improving Convergence of Replica-Exchange Simulations through Coupling to a High-Temperature Structure Reservoir

2007 ◽  
Vol 3 (2) ◽  
pp. 557-568 ◽  
Author(s):  
Asim Okur ◽  
Daniel R. Roe ◽  
Guanglei Cui ◽  
Viktor Hornak ◽  
Carlos Simmerling
Keyword(s):  
High Temperature ◽  
Replica Exchange ◽  
Temperature Structure ◽  
High Temperature Structure

scholarly journals The inverse perovskite BaLiF3: single-crystal neutron diffraction and analyses of potential ion pathways

2018 ◽  
Vol 74 (6) ◽  
pp. 643-650 ◽  
Author(s):  
Dennis Wiedemann ◽  
Falk Meutzner ◽  
Oscar Fabelo ◽  
Steffen Ganschow
Keyword(s):  
High Temperature ◽  
Neutron Diffraction ◽  
Scattering Length ◽  
Temperature Structure ◽  
Luminescent Materials ◽  
Lithium Ions ◽  
Ion Migration ◽  
Mobile Species ◽  
Tolerance Factors ◽  
Migration Pathways

Doped barium lithium trifluoride has attracted attention as component for scintillators, luminescent materials and electrodes. With lithium and fluoride, it contains two possibly mobile species, which may account for its ionic conductivity. In this study, neutron diffraction on oxide-containing BaLiF3 single-crystals is performed at up to 636.2°C. Unfortunately, ion-migration pathways could not be mapped by modelling anharmonic ion displacement or by inspecting the scattering-length density that was reconstructed via maximum-entropy methods. However, analyses of the topology and bond-valence site energies derived from the high-temperature structure reveal that the anions can migrate roughly along the edges of the LiF6 coordination octahedra with an estimated migration barrier of ∼0.64 eV (if a vacancy permits), whereas the lithium ions are confined to their crystallographic positions. This finding is not only valid for the title compound but for ion migration in all perovskites with Goldschmidt tolerance factors near unity.

High Temperature Structure Stability Study on Nb-Containing Nickel-Base Superalloys

2007 ◽  
Vol 546-549 ◽  
pp. 1281-1288 ◽  
Author(s):  
Xi Shan Xie ◽  
Jian Xin Dong ◽  
Mai Cang Zhang ◽  
Shu Hong Fu
Keyword(s):  
High Temperature ◽  
Phase Formation ◽  
Inconel 718 ◽  
Phase Changes ◽  
Stable Phase ◽  
Structure Stability ◽  
Temperature Structure ◽  
Alloy 718 ◽  
Strengthening Phases ◽  
High Temperature Structure

High temperature structure stability of 2 important Nb-containing Ni-base superalloys Inconel 718 (Ni-19Cr-18Fe-3Mo-5Nb-1Ti-0.5Al) and Inconel 740 (Ni-25Cr-20Co-0.5Mo-2Nb -1.8Ti-0.8Al) have been studied on the relationship of microstructure to mechanical properties via SEM, TEM, SAD, XRD and quantitative determination of precipitated phases by micro-chemical analysis. The longest exposure times are 50,000hrs at 650°C for Alloy 718 and 4,000hrs at 704°C, 725°C and 760°C for Alloy 740. The structure instabilities for these 2 Alloys are: 1) strengthening phases γ″/γ′ coarsening; 2) meta-stable strengthening phases change to stable phase, such as γ″→ δ-Ni3Nb for Alloy 718 and γ′→ η-Ni3Ti for Alloy 740; 3) embrittling phases formation, such as α-Cr and σ-phase formation in Alloy 718 and high Si-containing G-phase formation in Alloy 740. On the base of understanding phase changes at high temperature exposures the structure stability of Inconel 718 and Inconel 740 has been improved both by minor adjustment of alloys chemistry. The modifications of Alloy 718 and Alloy 740 are to be developed in the near future.

Unusual complex high temperature structure of Fe2VSi

2006 ◽  
Vol 417 (1-2) ◽  
pp. 150-154 ◽  
Author(s):  
O. Nashima ◽  
Y. Yamaguchi ◽  
H. Higashi ◽  
T. Goto ◽  
T. Kaneko ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Structure ◽  
High Temperature Structure
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