A sapphire single-crystal cell for in situ neutron powder diffraction of solid-gas reactions

2018 ◽  
Vol 551 ◽  
pp. 395-400 ◽  
Author(s):  
A. Götze ◽  
H. Auer ◽  
R. Finger ◽  
T.C. Hansen ◽  
H. Kohlmann
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
Crystal Cell ◽  
Sapphire Single Crystal ◽  
Gas Reactions

scholarly journals Design and use of a sapphire single-crystal gas-pressure cell for in situ neutron powder diffraction

2021 ◽  
Vol 54 (3) ◽  
Author(s):  
Raphael Finger ◽  
Nadine Kurtzemann ◽  
Thomas C. Hansen ◽  
Holger Kohlmann
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
Gas Pressure ◽  
Sample Holder ◽  
Pressure Cell ◽  
Hydrogen Deuterium ◽  
Sapphire Single Crystal ◽  
Deuterium Gas

A sapphire single-crystal gas-pressure cell without external support allowing unobstructed optical access by neutrons has been developed and optimized for elastic in situ neutron powder diffraction using hydrogen (deuterium) gas at the high-intensity two-axis diffractometer D20 at the Institut Laue-Langevin (Grenoble, France). Given a proper orientation of the single-crystal sample holder with respect to the detector, parasitic reflections from the sample holder can be avoided and the background can be kept low. Hydrogen (deuterium) gas pressures of up to 16.0 MPa at 298 K and 8.0 MPa at 655 K were tested successfully for a wall thickness of 3 mm. Heating was achieved by a two-sided laser heating system. The typical time resolution of in situ investigations of the reaction pathway of hydrogen (deuterium) uptake or release is on the order of 1 min. Detailed descriptions of all parts of the sapphire single-crystal gas-pressure cell are given, including materials information, technical drawings and instructions for use.

scholarly journals Air-heated solid–gas reaction setup for in situ neutron powder diffraction

2019 ◽  
Vol 52 (4) ◽  
pp. 761-768 ◽  
Author(s):  
Jakob Voldum Ahlburg ◽  
Emmanuel Canévet ◽  
Mogens Christensen
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Time Resolution ◽  
Temperature Stability ◽  
Sample Volume ◽  
Industrial Applications ◽  
Neutron Powder Diffraction ◽  
Advanced Materials ◽  
Air Gun

The design and function of a reduction furnace, specially designed for solid–gas in situ monochromatic angular dispersive neutron powder diffraction, is presented. The functionality is demonstrated by performing a reduction experiment of CoFe2O4 nanoparticles at the instrument DMC at SINQ. Heating is provided by an air gun, allowing the sample to reach temperatures in the range of 300–973 K within less than 5 min. The setup is based on a single-crystal sapphire tube with one end closed. A φ scan of the tube reveals its single-crystal nature, through strong single-crystal reflections, while the remaining background is very low, uniform and flat. CoFe2O4 was reduced using a time resolution of 8 min and a sample volume of ∼2 cm3. By means of sequential Rietveld refinement of the in situ neutron diffraction data, a two-step reduction mechanism was discovered: CoFe2O4 → Co0.33Fe0.67O → CoFe2. The setup offers high temperatures, fast temperature stability, large sample volumes and respectable time resolution. The setup has proven to be ideal to carry out investigations of advanced materials under realistic conditions. The ability to investigate real materials in real time under realistic conditions may be a significant advantage for scientific investigations as well as for industrial applications.

In Situ Neutron Powder Diffraction Study of Ti3SiC2 Synthesis

2004 ◽  
Vol 84 (10) ◽  
pp. 2281-2288 ◽  
Author(s):  
Erdong Wu ◽  
Erich H. Kisi ◽  
Shane J. Kennedy ◽  
Andrew J. Studer
Keyword(s):  
Diffraction Study ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction

Oxygen Ordered Phases in LaxSr1−xMnOy(0 ≤x≤ 0.2, 2.5 ≤ y ≤ 3): An In situ Neutron Powder Diffraction Study

2008 ◽  
Vol 20 (4) ◽  
pp. 1636-1645 ◽  
Author(s):  
Leopoldo Suescun ◽  
Bogdan Dabrowski ◽  
James Mais ◽  
Steven Remsen ◽  
James W. Richardson ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
Ordered Phases

Mn-Mg disordering in cummingtonite: a high-temperature neutron powder diffraction study

2000 ◽  
Vol 64 (2) ◽  
pp. 255-266 ◽  
Author(s):  
J. J. Reece ◽  
S. A. T. Redfern ◽  
M. D. Welch ◽  
C. M. B. Henderson
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
New York ◽  
High Temperature ◽  
Powder Diffraction ◽  
Elevated Temperatures ◽  
Neutron Powder Diffraction ◽  
Site Preference ◽  
A Site

AbstractThe crystal structure of a manganoan cummingtonite, composition [M4](Na0.13Ca0.41Mg0.46Mn1.00) [M1,2,3](Mg4.87Mn0.13)(Si8O22)(OH)2, (Z = 2), a = 9.5539(2) Å, b = 18.0293(3) Å, c = 5.2999(1) Å, β = 102.614(2)° from Talcville, New York, has been refined at high temperature using in situ neutron powder diffraction. The P21/m to C2/m phase transition, observed as spontaneous strains +ε1 = −ε2, occurs at ˜107°C. Long-range disordering between Mg2+ and Mn2+ on the M(4) and M(2) sites occurs above 550°C. Mn2+ occupies the M(4) and M(2) sites preferring M(4) with a site-preference energy of 24.6±1.5 kJ mol−1. Disordering induces an increase in XMnM2 and decrease in XMnM4 at elevated temperatures. Upon cooling, the ordered states of cation occupancy are ‘frozen in’ and strains in lattice parameters are maintained, suggesting that re-equilibration during cooling has not taken place.

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