Effect of sulfur on diamond growth and morphology in metal–carbon systems

CrystEngComm ◽  
2020 ◽  
Vol 22 (33) ◽  
pp. 5497-5508
Author(s):  
Yuri N. Palyanov ◽  
Yuri M. Borzdov ◽  
Alexander F. Khokhryakov ◽  
Yuliya V. Bataleva ◽  
Igor N. Kupriyanov
Keyword(s):  
Crystal Morphology ◽  
Diamond Crystal ◽  
Impurity Content ◽  
Diamond Growth ◽  
Nitrogen Impurity ◽  
Diamond Crystallization

Sulfur additives inhibit diamond crystallization in the Fe–Ni–C system at 6 GPa and 1400 °C and affect the diamond crystal morphology and nitrogen impurity content.

scholarly journals Effect of Rare-Earth Element Oxides on Diamond Crystallization in Mg-Based Systems

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 300 ◽  
Author(s):  
Yuri N. Palyanov ◽  
Yuri M. Borzdov ◽  
Alexander F. Khokhryakov ◽  
Igor N. Kupriyanov
Keyword(s):  
Rare Earth ◽  
Crystal Morphology ◽  
Diamond Crystal ◽  
Rare Earth Oxide ◽  
Emission Characteristic ◽  
Inhibiting Effect ◽  
Diamond Crystals ◽  
Growth System ◽  
Diamond Crystallization ◽  
Mass Crystallization

Diamond crystallization in Mg-R2O3-C systems (R = Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb) was studied at 7.8 GPa and 1800 °C. It was found that rare-earth oxide additives in an amount of 10 wt % did not significantly affect both the degree of graphite-to-diamond conversion and crystal morphology relative to the Mg-C system. The effect of higher amounts of rare-earth oxide additives on diamond crystallization was studied for a Mg-Sm2O3-C system with a Sm2O3 content varied from 0 to 50 wt %. It was established that with an increase in the Sm2O3 content in the growth system, the degree of graphite-to-diamond conversion decreased from 80% at 10% Sm2O3 to 0% at 40% Sm2O3. At high Sm2O3 contents (40 and 50 wt %), instead of diamond, mass crystallization of metastable graphite was established. The observed changes in the degree of the graphite-to-diamond conversion, the changeover of diamond crystallization to the crystallization of metastable graphite, and the changes in diamond crystal morphology with increasing the Sm2O3 content attested the inhibiting effect of rare-earth oxides on diamond crystallization processes in the Mg-Sm-O-C system. The crystallized diamonds were studied by a suite of optical spectroscopy techniques, and the major characteristics of their defect and impurity structures were revealed. For diamond crystals produced with 10 wt % and 20 wt % Sm2O3 additives, a specific photoluminescence signal comprising four groups of lines centered at approximately 580, 620, 670, and 725 nm was detected, which was tentatively assigned to emission characteristic of Sm3+ ions.

Doping of Diamond Crystals with a Dopant of P3N5

2012 ◽  
Vol 217-219 ◽  
pp. 96-100
Author(s):  
You Jin Zheng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diamond Crystal ◽  
Nitrogen Concentration ◽  
Diamond Growth ◽  
Ir Absorption ◽  
Xps Spectra ◽  
Diamond Crystals ◽  
Growth Method ◽  
Heavily Doped ◽  
Ppm Level

In this paper, a new dopant of P3N5 (phosphorus nitride) was doped into the diamond growth cell to grow diamond crystals by temperature gradient growth method (TGM) under high pressure and high temperature (HPHT). The experiments were performed at a fixed pressure of about 6.0 GPa and temperatures of 1600-1650 K. The gained diamond crystals were characterized by infrared (IR) absorption spectroscopy, micro-Raman spectroscopy and X-ray photoelectron spectroscopy (XPS), respectively. IR measurements demonstrated that, nitrogen atom was indeed doped into diamond crystals, and the diamond crystals with perfect shape containing nitrogen concentration ranging from 461 atomic parts per million (ppm) to 2186 atomic ppm were successfully synthesized. Nitrogen atoms present in diamond crystal were predominantly in isolated form accompanied by a small amount of nitrogen pairs. Micro-Raman spectra implied that crystalline quality deteriorated with nitrogen concentration gradually increased in diamond-growing environment. The XPS spectra revealed that only a few of phosphorus impurities about tens of ppm level were incorporated into a diamond crystal which was heavily doped with P3N5. This study will promote the application of doping diamonds in micro-electronics field and other fields.

scholarly journals How do diamonds grow in metal melt together with silicate minerals? An experimental study of diamond morphology

2020 ◽  
Vol 32 (1) ◽  
pp. 41-55
Author(s):  
Aleksei Chepurov ◽  
Valery Sonin ◽  
Jean-Marie Dereppe ◽  
Egor Zhimulev ◽  
Anatoly Chepurov
Keyword(s):  
Natural Diamond ◽  
Diamond Growth ◽  
Chemical Compositions ◽  
Silicate Minerals ◽  
Metal Melt ◽  
Origin And Evolution ◽  
Metal Melts ◽  
Reducing Conditions ◽  
Diamond Crystallization ◽  
The Stability

Abstract. The origin and evolution of metal melts in the Earth's mantle and their role in the formation of diamond are the subject of active discussion. It is widely accepted that portions of metal melts in the form of pockets can be a suitable medium for diamond growth. This raises questions about the role of silicate minerals that form the walls of these pockets and are present in the volume of the metal melt during the growth of diamonds. The aim of the present work was to study the crystallization of diamond in a complex heterogeneous system: metal-melt–basalt–carbon. The experiments were performed using a multianvil high-pressure apparatus of split-sphere type (BARS) at a pressure of 5.5 GPa and a temperature of 1500 ∘C. The results demonstrated crystallization of diamond in metal melt together with garnet and clinopyroxene, whose chemical compositions are similar to those of eclogitic inclusions in natural diamond. We show that the presence of silicates in the crystallization medium does not reduce the chemical ability of metal melts to catalyze the conversion of graphite into diamond, and, morphologically, diamond crystallizes mainly in the form of a cuboctahedron. When the content of the silicate material in the system exceeds 5 wt %, diamond forms parallel-growth aggregates, but 15 wt % of silicate phases block the crystallization chamber, preventing the penetration of metallic melt into them, thus interrupting the growth of diamond. We infer that the studied mechanism of diamond crystallization can occur at lower-mantle conditions but could also have taken place in the ancient continental mantle of the Earth, under reducing conditions that allowed the stability of Fe–Ni melts.

Regulation mechanism of catalyst structure on diamond crystal morphology under HPHT process

2020 ◽  
Vol 29 (7) ◽  
pp. 078101
Author(s):  
Ya-Dong Li ◽  
Yong-Shan Cheng ◽  
Meng-Jie Su ◽  
Qi-Fu Ran ◽  
Chun-Xiao Wang ◽  
...  
Keyword(s):  
Crystal Morphology ◽  
Diamond Crystal ◽  
Regulation Mechanism ◽  
Catalyst Structure

scholarly journals Crystallization of Diamond from Melts of Europium Salts

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 376 ◽  
Author(s):  
Yuri M. Borzdov ◽  
Alexander F. Khokhryakov ◽  
Igor N. Kupriyanov ◽  
Denis V. Nechaev ◽  
Yuri N. Palyanov
Keyword(s):  
Growth Rate ◽  
Maximum Growth ◽  
Spectroscopic Characterization ◽  
Maximum Growth Rate ◽  
Diamond Growth ◽  
Diamond Nucleation ◽  
System Composition ◽  
Diamond Crystallization ◽  
High Concentrations ◽  
First Time

Diamond crystallization in melts of europium salts (Eu2(C2O4)3·10H2O, Eu2(CO3)3·3H2O, EuCl3, EuF3, EuF2) at 7.8 GPa and in a temperature range of 1800–2000 °C was studied for the first time. Diamond growth on seed crystals was realized at a temperature of 2000 °C. Spontaneous diamond nucleation at these parameters was observed only in an Eu oxalate melt. The maximum growth rate in the europium oxalate melt was 22.5 μm/h on the {100} faces and 12.5 μm/h on the {111} faces. The diamond formation intensity in the tested systems was found to decrease in the following sequence: Eu2(C2O4)3·10H2O > Eu2(CO3)3·3H2O > EuF3 > EuF2 = EuCl3. Diamond crystallization occurred in the region of stable octahedral growth in melts of Eu3+ salts and in the region of cubo-octahedral growth in an EuF2 melt. The microrelief of faces was characterized by specific features, depending on the system composition and diamond growth rate. In parallel with diamond growth, the formation of metastable graphite in the form of independent crystals and inclusions in diamond was observed. From the spectroscopic characterization, it was found that diamonds synthesized from Eu oxalate contain relatively high concentrations of nitrogen (about 1000−1200 ppm) and show weak PL features due to inclusions of Eu-containing species.

Effects of catalyst height on diamond crystal morphology under high pressure and high temperature

2016 ◽  
Vol 25 (4) ◽  
pp. 048103
Author(s):  
Ya-Dong Li ◽  
Xiao-Peng Jia ◽  
Bing-Min Yan ◽  
Ning Chen ◽  
Chao Fang ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Crystal Morphology ◽  
Diamond Crystal

Effect of Nitrogen Impurity on Diamond Crystal Growth Processes

2010 ◽  
Vol 10 (7) ◽  
pp. 3169-3175 ◽  
Author(s):  
Yuri N. Palyanov ◽  
Yuri M. Borzdov ◽  
Alexander F. Khokhryakov ◽  
Igor N. Kupriyanov ◽  
Alexander G. Sokol
Keyword(s):  
Crystal Growth ◽  
Diamond Crystal ◽  
Growth Processes ◽  
Nitrogen Impurity

Correlation between the Nitrogen Impurity Content and the Crystal Habit of Synthetic Diamond

Nature ◽  
1968 ◽  
Vol 218 (5148) ◽  
pp. 1246-1247 ◽  
Author(s):  
B. R. ANGEL ◽  
M. J. A. SMITH ◽  
J. J. CHARETTE
Keyword(s):  
Synthetic Diamond ◽  
Impurity Content ◽  
Crystal Habit ◽  
Nitrogen Impurity

“Preparation of Single Crystalline Gold Films for ED Studies”

1972 ◽  
Vol 30 ◽  
pp. 634-635
Author(s):  
Joseph D. C. Peng
Keyword(s):  
Crystal Morphology ◽  
Diffraction Theory ◽  
Scattering Matrix ◽  
Vacuum Evaporation ◽  
Gold Films ◽  
Matrix Formulation ◽  
Silver Films ◽  
Single Crystalline ◽  
Grating Pattern ◽  
Stacking Disorder

The relative intensities of the ED spots in a cross-grating pattern can be calculated using N-beam electron diffraction theory. The scattering matrix formulation of N-beam ED theory has been previously applied to imperfect microcrystals of gold containing stacking disorder (coherent twinning) in the (111) crystal plane. In the present experiment an effort has been made to grow single-crystalline, defect-free (111) gold films of a uniform and accurately know thickness using vacuum evaporation techniques. These represent stringent conditions to be met experimentally; however, if a meaningful comparison is to be made between theory and experiment, these factors must be carefully controlled. It is well-known that crystal morphology, perfection, and orientation each have pronounced effects on relative intensities in single crystals.The double evaporation method first suggested by Pashley was employed with some modifications. Oriented silver films of a thickness of about 1500Å were first grown by vacuum evaporation on freshly cleaved mica, with the substrate temperature at 285° C during evaporation with the deposition rate at 500-800Å/sec.

The value of Electron Microscope studies of imperfect natural diamonds

1990 ◽  
Vol 48 (4) ◽  
pp. 194-195
Author(s):  
J C Walmsley ◽  
A R Lang
Keyword(s):  
Electron Microscope ◽  
Classification Scheme ◽  
Natural Diamond ◽  
Sudden Change ◽  
Growth Conditions ◽  
Diamond Growth ◽  
Major Constituent ◽  
Natural Diamonds ◽  
Type Ia ◽  
Platelet Defects

Interest in the defects and impurities in natural diamond, which are found in even the most perfect stone, is driven by the fact that diamond growth occurs at a depth of over 120Km. They display characteristics associated with their origin and their journey through the mantle to the surface of the Earth. An optical classification scheme for diamond exists based largely on the presence and segregation of nitrogen. For example type Ia, which includes 98% of all natural diamonds, contain nitrogen aggregated into small non-paramagnetic clusters and usually contain sub-micrometre platelet defects on {100} planes. Numerous transmission electron microscope (TEM) studies of these platelets and associated features have been made e.g. . Some diamonds, however, contain imperfections and impurities that place them outside this main classification scheme. Two such types are described.First, coated-diamonds which possess gem quality cores enclosed by a rind that is rich in submicrometre sized mineral inclusions. The transition from core to coat is quite sharp indicating a sudden change in growth conditions, Figure 1. As part of a TEM study of the inclusions apatite has been identified as a major constituent of the impurity present in many inclusion cavities, Figure 2.

Sign in / Sign up

Export Citation Format

Share Document