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.

The characterization of strain, impurity content, and crush strength of synthetic diamond crystals

1997 ◽  
Vol 12 (1) ◽  
pp. 253-263 ◽  
Author(s):  
Terri L. McCormick ◽  
W. E. Jackson ◽  
R. J. Nemanich
Keyword(s):  
High Pressure ◽  
High Strain ◽  
Synthetic Diamond ◽  
Impurity Content ◽  
Inclusion Content ◽  
Diamond Crystals ◽  
High Pressure High Temperature ◽  
Two Samples ◽  
Crush Strength

This study addresses the correlation of the macroscopic and microscopic characteristics of synthetic diamond crystals produced by high pressure, high temperature conditions. Microscopic properties were characterized using Raman spectroscopy, birefringence, and photoluminescence (PL). Macroscopic properties characterized included inclusion content and crush force. Raman measurements detected measurable stress shifts in only two samples. The PL measurements indicated an increased presence of the H3 center in areas of high strain. The absence of the H3 center and the presence of the N-V PL center was correlated to lower average crush force. A hierarchy has been developed that relates microscopic properties to average crush force.

Synthetic diamond crystal strength enhancement through annealing at 50 kbar and 1500 °C

1995 ◽  
Vol 10 (7) ◽  
pp. 1700-1709 ◽  
Author(s):  
Steven W. Webb ◽  
W.E. Jackson
Keyword(s):  
Diamond Crystal ◽  
Synthetic Diamond ◽  
Diamond Lattice ◽  
Type I ◽  
Strength Enhancement ◽  
High Metal Content ◽  
Diamond Crystals ◽  
High Pressure High Temperature ◽  
High Metal ◽  
Low Levels

High-pressure, high temperature (HPHT) annealing of synthetic type I diamond crystals at 1200–1700 °C and 50–60 kbar was found to induce aggregate-nitrogen dissociation and metal coalescence as well as heal diamond lattice dislocations. For crystals with low levels of metal inclusions, HPHT annealing was observed to increase the average compressive fracture strength of the crystals by apparently strengthening the strongest crystals of the population. Crystals with high metal-content, or otherwise of low quality, are weakened by anncaling. Strengthening is believed to occur by locally stabilizing the diamond lattice by healing lattice dislocations as well as dispersing nitrogen within the lattice. A general model is presented that ties together these results with those of other researchers.

scholarly journals Superhard Superconductor Composites Obtained by Sintering of Diamond, c-BN and C60 Powders with Superconductors

2006 ◽  
Vol 61 (12) ◽  
pp. 1541-1546 ◽  
Author(s):  
Gennadi A. Dubitsky ◽  
Vladimir D. Blank ◽  
Sergei G. Buga ◽  
Elena E. Semenova ◽  
Nadejda R. Serebryanaya ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Critical Temperature ◽  
Boron Nitride ◽  
Synthetic Diamond ◽  
Cubic Boron Nitride ◽  
High Pressure High Temperature ◽  
Diamond Powders

Superhard superconducting samples with a critical temperature of TC = 10.5 - 12.6 K were obtained by high-pressure / high-temperature sintering of synthetic diamond powders coated with a niobium film and in 50% - 50% composition with superhard C60 fullerene. Superhard superconductors with TC = 9.3 K were obtained when diamond and molybdenum powders were sintered at a pressure of 7.7 GPa and a temperature of 2173 K. Superconducting samples with TC = 36.1 - 37.5 K have been obtained in the systems diamond-MgB2 and cubic boron nitride-MgB2.

TEM and DSC Studies on the Synthetic Diamond Grown from Fe-Ni-C-B System under HPHT

2011 ◽  
Vol 320 ◽  
pp. 3-7
Author(s):  
Jian Hong Gong ◽  
Shu Xia Lin ◽  
Jun Gao
Keyword(s):  
Thermal Stability ◽  
Boron Content ◽  
Synthetic Diamond ◽  
Scanning Calorimetry ◽  
Dsc Studies ◽  
Diamond Crystals ◽  
Transmission Electron ◽  
High Pressure High Temperature ◽  
Alloy Catalysts ◽  
Thermal Stability Of

Transmission Electron Microscope (TEM) and Different Scanning Calorimetry (DSC) Methods Were Used to Investigate the Diamonds Grown with Different Boron Content Alloy Catalysts under High-Pressure High-Temperature (HPHT). Experimental Results Demonstrated the Microstructure and Composition of Boride Compounds in Synthetic Diamond, such as (FeNi)23(CB)6 ,(Fe, Ni)3(C,B), (Fe,Ni)B and B4C, Whose Formation Process Was Analyzed. the Thermal Stability of Diamond Depends on Boron Concentration in Catalyst According to DSC Studies. we Analyzed the Reason of Diamond Oxidation.The Work Offers Valuable Information for Improving the Thermal Stability of Synthetic Diamond Crystals by Adjusting Boron Content in the Fe-Ni Based Catalyst.

The Use of Micro-Raman Spectroscopy to Monitor High-Pressure High-Temperature Annealing of Ion-Implanted GaN Films

1999 ◽  
Vol 595 ◽  
Author(s):  
M. Kuball ◽  
J.M. Hayes ◽  
T. Suski ◽  
J. Jun ◽  
H.H. Tan ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Surface Layer ◽  
High Temperature ◽  
Structural Quality ◽  
High Temperature Annealing ◽  
Micro Raman Spectroscopy ◽  
High Pressure High Temperature ◽  
Different Temperatures ◽  
Ion Implanted

AbstractWe have investigated the high-pressure high-temperature annealing of Mg/P-implanted GaN films using visible and ultraviolet (UV) micro-Raman spectroscopy. The results illustrate the use of Raman spectroscopy to monitor processing of GaN where fast feedback is required. The structural quality and the stress in ion-implanted GaN films was monitored in a 40nm-thin surface layer of the sample as well as averaged over the sample layer thickness. We find the nearly full recovery of the crystalline quality of ion-implanted GaN films after annealing at 1400-1500°C under nitrogen overpressures of 1.5GPa. No significant degradation effects occurred in the GaN surface layer during the annealing. The high nitrogen overpressures proved very effective in preventing the nitrogen out-diffusion from the GaN surface. Stress introduced during the annealing was monitored. Raman spectra of ion-implanted GaN films were investigated at different temperatures and excitation wavelengths to study the GaN phonon density of states.

scholarly journals The Use of Micro-Raman Spectroscopy to Monitor High-Pressure High Temperature Annealing of Ion-Implanted GaN Films

2000 ◽  
Vol 5 (S1) ◽  
pp. 740-746
Author(s):  
M. Kuball ◽  
J.M. Hayes ◽  
T. Suski ◽  
J. Jun ◽  
H.H. Tan ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Surface Layer ◽  
High Temperature ◽  
Structural Quality ◽  
High Temperature Annealing ◽  
Micro Raman Spectroscopy ◽  
High Pressure High Temperature ◽  
Different Temperatures ◽  
Ion Implanted

We have investigated the high-pressure high-temperature annealing of Mg/P-implanted GaN films using visible and ultraviolet (UV) micro-Raman spectroscopy. The results illustrate the use of Raman spectroscopy to monitor processing of GaN where fast feedback is required. The structural quality and the stress in ion-implanted GaN films was monitored in a 40nm-thin surface layer of the sample as well as averaged over the sample layer thickness. We find the nearly full recovery of the crystalline quality of ion-implanted GaN films after annealing at 1400-1500°C under nitrogen overpressures of 1.5GPa. No significant degradation effects occurred in the GaN surface layer during the annealing. The high nitrogen overpressures proved very effective in preventing the nitrogen out-diffusion from the GaN surface. Stress introduced during the annealing was monitored. Raman spectra of ion-implanted GaN films were investigated at different temperatures and excitation wavelengths to study the GaN phonon density of states.

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.

A Study of Free- and Bound-Exciton Recombination in Device Quality Diamond

1995 ◽  
Vol 416 ◽  
Author(s):  
S. J. Sharp ◽  
A. T. Collins
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Temperature Dependence ◽  
High Purity ◽  
Vapour Deposition ◽  
Synthetic Diamond ◽  
Free Exciton ◽  
Chemical Vapour ◽  
High Pressure High Temperature ◽  
Exciton Recombination

ABSTRACTA cathodoluminescence (CL) study of free- and bound-exciton recombination in high purity high pressure high temperature (HPHT) synthetic diamond is presented, including temperature dependence measurements of the free-exciton intensity and luminescence decaytime. The results are compared with those from device quality diamond produced using the chemical vapour deposition (CVD) process.

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