In situ observation of transformation of neutron-irradiated highly oriented pyrolytic graphite (HOPG) by X-ray diffraction under high-pressure and high-temperature treatment

Author(s):  
Shin-ichi Honda ◽  
Yuji Higo ◽  
Keisuke Niwase ◽  
Masahito Niibe ◽  
Mititaka Terasawa ◽  
...  
2018 ◽  
Vol 25 (6) ◽  
pp. 1673-1682 ◽  
Author(s):  
Adam S. Hoffman ◽  
Joseph A. Singh ◽  
Stacey F. Bent ◽  
Simon R. Bare

In situ characterization of catalysts gives direct insight into the working state of the material. Here, the design and performance characteristics of a universal in situ synchrotron-compatible X-ray diffraction cell capable of operation at high temperature and high pressure, 1373 K, and 35 bar, respectively, are reported. Its performance is demonstrated by characterizing a cobalt-based catalyst used in a prototypical high-pressure catalytic reaction, the Fischer–Tropsch synthesis, using X-ray diffraction. Cobalt nanoparticles supported on silica were studied in situ during Fischer–Tropsch catalysis using syngas, H2 and CO, at 723 K and 20 bar. Post reaction, the Co nanoparticles were carburized at elevated pressure, demonstrating an increased rate of carburization compared with atmospheric studies.


2019 ◽  
Vol 39 (3) ◽  
pp. 499-508 ◽  
Author(s):  
Chikara Shito ◽  
Keitaro Okamoto ◽  
Yuki Sato ◽  
Ryuji Watanabe ◽  
Tomonori Ohashi ◽  
...  

1998 ◽  
Vol 547 ◽  
Author(s):  
J.-H. Park ◽  
P.M. Woodward ◽  
J.B. Parise ◽  
I. Lubomirsky ◽  
O. Stafsudd

AbstractA new perovskite was recovered from the high pressure-high temperature treatment of the α-TlSbO3 form of Na2SnTeO6 at 7 GPa and 950 °C for 30 minutes. Synchrotron x-ray powder diffraction data show the space group is P21/n with a=5.40361 (5), b=5.46152(5), c=7.69288(7) Å and ß=90.034(3)°. Using disk samples of both polymorphs, the dielectric properties were measured as a function of temperature. At ambient conditions, the perovskite form has a more than 1.5 fold enhancement in dielectric constant compared to the α-TlSbO3 form while the molar volume and the molecular polarizability decrease.


2011 ◽  
Vol 197-198 ◽  
pp. 499-502
Author(s):  
Zheng He Hua ◽  
Heng Zhang ◽  
Ju Peng

Superconducting SmFeAsO0.8F0.2 compound was successfully synthesized by high pressure high temperature treatment with pressure of 6 G Pa at 1400 °C for 2 hours. The X-ray diffraction pattern of the sample indicates the formation of the tetragonal ZrCuSiAs-type SmFeAsO0.8F0.2 with lattice parameters a=3.932 Å and c=8.490 Å. The electrical transport study shows that the sample has a rather high transition temperature Tc of about 52 K, and magnetic field effect on the resistance reveals a rather high upper critical field HC2 of about 65 T.


1995 ◽  
Vol 8 (4) ◽  
pp. 234-237 ◽  
Author(s):  
G M Zorn ◽  
R Hornung ◽  
H E Gobel ◽  
B Seebacher ◽  
H W Neumuller ◽  
...  

2012 ◽  
Vol 29 (2) ◽  
pp. 026102 ◽  
Author(s):  
Ting-Ting Gu ◽  
Xiang Wu ◽  
Shan Qin ◽  
Jing Liu ◽  
Yan-Chun Li ◽  
...  

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