scholarly journals Neutron diffraction and gravimetric study of the manganese nitriding reaction under ammonia decomposition conditions

2018 ◽  
Vol 20 (13) ◽  
pp. 8547-8553 ◽  
Author(s):  
Thomas J. Wood ◽  
Joshua W. Makepeace ◽  
William I. F. David

In situ neutron diffraction of ammonia decomposition over manganese reveals the structures of different nitrides and kinetic information about their formation.

2017 ◽  
Vol 19 (40) ◽  
pp. 27859-27865 ◽  
Author(s):  
Thomas J. Wood ◽  
Joshua W. Makepeace ◽  
William I. F. David

In situ neutron diffraction of the ammonia decomposition reaction over iron shows the catalyst to be Fe or Fe4N depending on the conditions.


2020 ◽  
Author(s):  
Satoshi Morooka ◽  
Nobuo Nakada ◽  
Yuhki Tsukada ◽  
Wu Gong ◽  
Takuro Kawasaki ◽  
...  

2019 ◽  
Vol 9 (7) ◽  
pp. 1310 ◽  
Author(s):  
Kerstin Hauke ◽  
Johannes Kehren ◽  
Nadine Böhme ◽  
Sinje Zimmer ◽  
Thorsten Geisler

In the last decades, Raman spectroscopy has become an important tool to identify and investigate minerals, gases, glasses, and organic material at room temperature. In combination with high-temperature and high-pressure devices, however, the in situ investigation of mineral transformation reactions and their kinetics is nowadays also possible. Here, we present a novel approach to in situ studies for the sintering process of silicate ceramics by hyperspectral Raman imaging. This imaging technique allows studying high-temperature solid-solid and/or solid-melt reactions spatially and temporally resolved, and opens up new avenues to study and visualize high-temperature sintering processes in multi-component systems. After describing in detail the methodology, the results of three application examples are presented and discussed. These experiments demonstrate the power of hyperspectral Raman imaging for in situ studies of the mechanism(s) of solid-solid or solid-melt reactions at high-temperature with a micrometer-scale resolution as well as to gain kinetic information from the temperature- and time-dependent growth and breakdown of minerals during isothermal or isochronal sintering.


2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Qian Li ◽  
Yun Liu ◽  
Andrew Studer ◽  
Zhenrong Li ◽  
Ray Withers ◽  
...  

We characterized the temperature dependent (~25–200°C) electromechanical properties and crystal structure of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3single crystals usingin situelectrical measurement and neutron diffraction techniques. The results show that the poled crystal experiences an addition phase transition around 120°C whereas such a transition is absent in the unpoled crystal. It is also found that the polar order persists above the maximum dielectric permittivity temperature at which the crystal shows a well-defined antiferroelectric behavior. The changes in the electrical properties and underlying crystal structure are discussed in the paper.


2015 ◽  
Vol 107 ◽  
pp. 29-32 ◽  
Author(s):  
Z.M. Shi ◽  
W. Gong ◽  
Y. Tomota ◽  
S. Harjo ◽  
J. Li ◽  
...  

2021 ◽  
Vol 139 ◽  
pp. 107371
Author(s):  
Haiyan He ◽  
Bing Wang ◽  
Dong Ma ◽  
Alexandru D. Stoica ◽  
Zhenduo Wu ◽  
...  

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