scholarly journals Experimental Study of Surface Etching in Synthetic Diamond Microcrystals due to Presence of Cu and Fe at High Pressure

2020 ◽  
pp. 18-21
Author(s):  
I.A. Ishutin ◽  
A.A. Chepurov ◽  
E.I. Zhimulev
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
Synthetic Diamond ◽  
Close Contact ◽  
High Pressure Cell ◽  
Diamond Composite ◽  
Refractory Oxides ◽  
Diamond Crystals ◽  
Composite Diamond ◽  
High Pressure Apparatus

In the present work, microcrystals of synthetic diamond extracted from a metal-diamond composite were investigated. A composite based on Cu and Fe was obtained by sintering at a pressure of 4 GPa and a temperature of1300 °C. The experiments were carried out using a split-sphere high-pressure apparatus BARS. The high-pressure cell was made of refractory oxides ZrO2, CaO, and MgO using a tubular graphite heater. In the composite, diamond grains were in close contact with neighboring diamonds, and the metal phase filled the interstices. The study of the diamond crystals demonstrated the appearance of newly formed micromorphological structures on the surfaces in the form of numerous cavities of irregular shape on the faces of octahedron, as well as pyramids on the faces of cube, the morphological elements of which follow the contours of the cube face of the diamond. Thus, the results of the work evidence for the processes of etching of the diamond crystals during the experiments, which is associated with the presence of metallic iron in the composite. This type of etching forms a roughly cavernous surface on the diamond crystals, which can be considered as an additional factor for improving the metal-diamond bond in copper-based composites.

scholarly journals Synthesis of gem diamond crystals by multiseed method using China-type cubic high-pressure apparatus

2013 ◽  
Vol 62 (18) ◽  
pp. 188103
Author(s):  
Hu Mei-Hua ◽  
Bi Ning ◽  
Li Shang-Sheng ◽  
Su Tai-Chao ◽  
Li Xiao-Lei ◽  
...  
Keyword(s):  
High Pressure ◽  
Diamond Crystals ◽  
High Pressure Apparatus

Strain and Impurity Content of Synthetic Diamond Crystals

1994 ◽  
Vol 349 ◽  
Author(s):  
T. L. Mccormick ◽  
W. E. Jackson ◽  
R.J. Nemanich
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Synthetic Diamond ◽  
Impurity Content ◽  
Nitrogen Forms ◽  
Inclusion Content ◽  
Diamond Crystals ◽  
High Pressure High Temperature ◽  
Photoluminescence Studies ◽  
Integrated Intensities

ABSTRACTSamples of diamond crystals produced under various high pressure, high temperature conditions were studied using both micro photoluminescence and Raman spectroscopy. The 0.3 - 0.6 mm sized samples exhibited various levels of inclusion content, impurity content and strain. Photoluminescence studies revealed the presence of nitrogen in three forms. The 1.945 eV, 2.15 eV and 2.46 eV zero phonon lines and their associated sidebands were detected. The ratios between forms of impurities and their integrated intensities varied between samples. Variations in the distribution of the nitrogen forms were seen between regions of high and low strain birefringence patterns.

scholarly journals Sulfide Formation as a Result of Sulfate Subduction into Silicate Mantle (Experimental Modeling under High P,T-Parameters)

Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 373 ◽  
Author(s):  
Yuliya Bataleva ◽  
Yuri Palyanov ◽  
Yuri Borzdov
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
Lithospheric Mantle ◽  
Experimental Modeling ◽  
Silicate Melt ◽  
Free System ◽  
Oxide Melt ◽  
High Pressure Apparatus

Ca,Mg-sulfates are subduction-related sources of oxidized S-rich fluid under lithospheric mantle P,T-parameters. Experimental study, aimed at the modeling of scenarios of S-rich fluid generation as a result of desulfation and subsequent sulfide formation, was performed using a multi-anvil high-pressure apparatus. Experiments were carried out in the Fe,Ni-olivine–anhydrite–C and Fe,Ni-olivine–Mg-sulfate–C systems (P = 6.3 GPa, T of 1050 and 1450 °C, t = 23–60 h). At 1050 °C, the interaction in the olivine–anhydrite–C system leads to the formation of olivine + diopside + pyrrhotite assemblage and at 1450 °C leads to the generation of immiscible silicate-oxide and sulfide melts. Desulfation of this system results in the formation of S-rich reduced fluid via the reaction olivine + anhydrite + C → diopside + S0 + CO2. This fluid is found to be a medium for the recrystallization of olivine, extraction of Fe and Ni, and subsequent crystallization of Fe,Ni-sulfides (i.e., olivine sulfidation). At 1450 °C in the Ca-free system, the generation of carbonate-silicate and Fe,Ni-sulfide melts occurs. Formation of the carbonate component of the melt occurs via the reaction Mg-sulfate + C → magnesite + S0. It is experimentally shown that the olivine-sulfate interaction can result in mantle sulfide formation and generation of potential mantle metasomatic agents—S- and CO2-dominated fluids, silicate-oxide melt, or carbonate-silicate melt.

scholarly journals Features of the internal structure of high-pressure metal-diamond composites

2020 ◽  
pp. 17-29
Author(s):  
Ilya Ishutin ◽  
◽  
Aleksei Chepurov ◽  
Egor Zhimulev ◽  
◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Iron Carbide ◽  
Iron Alloy ◽  
Metal Component ◽  
Industrial Synthesis ◽  
Diamond Crystals ◽  
High Pressure Apparatus ◽  
Alloy Iron ◽  
Intergranular Space

In the present work, composites were obtained by sintering a metal-diamond charge at a pressure of 4 GPa and a temperature of 1300°C. the experiments were carried out on a high-pressure apparatus of the split sphere “bars” type. Synthetic microcrystals of industrial synthesis were used as a diamond. The initial metal component for the experiments was copper and iron. it was shown that when sintering at high pressure, diamond crystals are tightly packed in the composite, while the metal phase completely fills the intergranular space, acting as a matrix. chemical analysis of the metal component of the samples revealed the presence of the following phases: copper-iron alloy, iron oxide and iron carbide. the results obtained indicate that several processes occur simultaneously in the diamond-copper-iron-oxygen system at high pressures and temperatures, which can significantly affect the characteristics of the resulting composite as a whole.

scholarly journals Use of a New Diamond Composite for Multianvil High-pressure Apparatus.

1992 ◽  
Vol 68 (10) ◽  
pp. 161-166 ◽  
Author(s):  
Tetsuo IRIFUNE ◽  
Wataru UTSUMI ◽  
Takehiko YAGI
Keyword(s):  
High Pressure ◽  
Diamond Composite ◽  
High Pressure Apparatus
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