scholarly journals Performance of Carbide Alloy Compounds in Carbon Doped MoNbTaW

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1073
Author(s):  
Congyan Zhang ◽  
Uttam Bhandari ◽  
Jialin Lei ◽  
Congyuan Zeng ◽  
Shengmin Guo ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
X Ray Diffraction ◽  
Complex Alloy ◽  
Carbon Doped ◽  
Refractory Elements ◽  
Diamond Anvil ◽  
The Stability ◽  
Bcc Phase

In this work, the performance of the carbon doped compositionally complex alloy (CCA) MoNbTaW was studied under ambient and high pressure and high temperature conditions. TaC and NbC carbides were formed when a large concentration of carbon was introduced while synthesizing the MoNbTaW alloy. Both FCC carbides and BCC CCA phases were detected in the sample compound at room temperature, in which the BCC phase was believed to have only refractory elements MoNbTaW while FCC carbide came from TaC and NbC. Carbides in the carbon doped MoNbTaW alloy were very stable since no phase transition was obtained even under 3.1 GPa and 870 °C by employing the resistor-heating diamond anvil cell (DAC) synchrotron X-ray diffraction technique. Via in situ examination, this study confirms the stability of carbides and MoNbTaW in the carbon doped CCA even under high pressure and high temperature.

The stability of Fe5O6 and Fe4O5 at high pressure and temperature

2019 ◽  
Vol 104 (9) ◽  
pp. 1356-1359
Author(s):  
Koutaro Hikosaka ◽  
Ryosuke Sinmyo ◽  
Kei Hirose ◽  
Takayuki Ishii ◽  
Yasuo Ohishi
Keyword(s):  
High Pressure ◽  
Iron Oxides ◽  
High Temperature Phase ◽  
Chemical Compositions ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Diamond Anvil ◽  
The Stability ◽  
Laser Heated

Abstract The oxygen fugacity in the interior of the Earth is largely controlled by iron-bearing minerals. Recent studies have reported various iron oxides with chemical compositions between FeO and Fe3O4 above ~10 GPa. However, the stabilities of these high-pressure iron oxides remain mostly uninvestigated. In this study, we performed in situ X-ray diffraction (XRD) measurements in a laser-heated diamond-anvil cell (DAC) to determine the phase relations in both Fe5O6 and Fe4O5 bulk compositions to 61 GPa and to 2720 K. The results show that Fe5O6 is a high-temperature phase stable above 1600 K and ~10 GPa, while FeO + Fe4O5 are formed at relatively low temperatures. We observed the decomposition of Fe5O6 into 2FeO + Fe3O4 above 38 GPa and the decomposition of Fe4O5 into FeO + h-Fe3O4 at a similar pressure range. The coexistence of FeO and Fe3O4 indicates that none of the recently discovered compounds between FeO and Fe3O4 (i.e., Fe5O6, Fe9O11, Fe4O5, and Fe7O9) are formed beyond ~40 GPa at 1800 K, corresponding to conditions in the shallow lower mantle. Additionally, as some superdeep diamonds have genetic links with these high-pressure iron oxides, our results give constraints on pressure and temperature conditions of their formation.

PHASE TRANSITION IN LAYERED PEROVSKITE LIKE MANGANATE Ca3Mn2O7 UNDER HIGH PRESSURE

2001 ◽  
Vol 15 (18) ◽  
pp. 2491-2497 ◽  
Author(s):  
J. L. ZHU ◽  
L. C. CHEN ◽  
R. C. YU ◽  
F. Y. LI ◽  
J. LIU ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Diamond Anvil Cell ◽  
The Other ◽  
Layered Perovskite ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Diamond Anvil

In situ high pressure energy dispersive X-ray diffraction measurements on layered perovskite-like manganate Ca 3 Mn 2 O 7 under pressures up to 35 GPa have been performed by using diamond anvil cell with synchrotron radiation. The results show that the structure of layered perovskite-like manganate Ca 3 Mn 2 O 7 is unstable under pressure due to the easy compression of NaCl-type blocks. The structure of Ca 3 Mn 2 O 7 underwent two phase transitions under pressures in the range of 0~35 GPa. One was at about 1.3 GPa with the crystal structure changing from tetragonal to orthorhombic. The other was at about 9.5 GPa with the crystal structure changing from orthorhombic back to another tetragonal.

In-situ X-ray diffraction study on β-CrOOH at high pressure and high-temperature

2019 ◽  
Vol 39 (3) ◽  
pp. 499-508 ◽  
Author(s):  
Chikara Shito ◽  
Keitaro Okamoto ◽  
Yuki Sato ◽  
Ryuji Watanabe ◽  
Tomonori Ohashi ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Diffraction Study ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Experimental method for in situ determination of material textures at simultaneous high pressure and high temperature by means of radial diffraction in the diamond anvil cell

2009 ◽  
Vol 80 (10) ◽  
pp. 104501 ◽  
Author(s):  
Hanns-Peter Liermann ◽  
Sébastien Merkel ◽  
Lowell Miyagi ◽  
Hans-Rudolf Wenk ◽  
Guoyin Shen ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Experimental Method ◽  
Diamond Anvil Cell ◽  
Diamond Anvil

A diamond anvil cell with resistive heating for high pressure and high temperature x-ray diffraction and absorption studies

2008 ◽  
Vol 79 (8) ◽  
pp. 085103 ◽  
Author(s):  
Sebastien Pasternak ◽  
Giuliana Aquilanti ◽  
Sakura Pascarelli ◽  
Roberta Poloni ◽  
Bernard Canny ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Diamond Anvil Cell ◽  
X Ray Diffraction ◽  
Resistive Heating ◽  
X Ray ◽  
Absorption Studies ◽  
Diamond Anvil

High-Pressure and High-Temperature in situ X-Ray Diffraction Study of FeP 2 up to 70 GPa

2012 ◽  
Vol 29 (2) ◽  
pp. 026102 ◽  
Author(s):  
Ting-Ting Gu ◽  
Xiang Wu ◽  
Shan Qin ◽  
Jing Liu ◽  
Yan-Chun Li ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Diffraction Study ◽  
X Ray Diffraction ◽  
X Ray

Structural stability of WS2 under high pressure

2014 ◽  
Vol 28 (25) ◽  
pp. 1450168 ◽  
Author(s):  
Nirup Bandaru ◽  
Ravhi S. Kumar ◽  
Jason Baker ◽  
Oliver Tschauner ◽  
Thomas Hartmann ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Structural Changes ◽  
High Pressures ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diamond Anvil ◽  
Heating Up

Structural behavior of bulk WS 2 under high pressure was investigated using synchrotron X-ray diffraction and diamond anvil cell up to 52 GPa along with high temperature X-ray diffraction and high pressure Raman spectroscopy analysis. The high pressure results obtained from X-ray diffraction and Raman analysis did not show any pressure induced structural phase transformations up to 52 GPa. The high temperature results show that the WS 2 crystal structure is stable upon heating up to 600°C. Furthermore, the powder X-ray diffraction obtained on shock subjected WS 2 to high pressures up to 10 GPa also did not reveal any structural changes. Our results suggest that even though WS 2 is less compressible than the isostructural MoS 2, its crystal structure is stable under static and dynamic compressions up to the experimental limit.

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