High Pressure and High Temperature Annealing of Ni-Containing, Nitrogen-rich Synthetic Diamonds and the Formation of NE8 Centers

2020 ◽  
Vol 20 (5) ◽  
pp. 3257-3263
Author(s):  
Liangchao Chen ◽  
Weixia Shen ◽  
Chao Fang ◽  
Yuewen Zhang ◽  
Peiyang Mu ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
High Temperature Annealing ◽  
Synthetic Diamonds

scholarly journals High pressure synthesis of BN and BCN crystals and their functionalization

2014 ◽  
Vol 70 (a1) ◽  
pp. C751-C751
Author(s):  
Takashi Taniguchi
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
High Purity ◽  
Chemical Vapour ◽  
Attractive Potential ◽  
Luminescence Spectra ◽  
Hard Material ◽  
High Temperature Annealing ◽  
Electrical Insulator ◽  
Carbon Impurity

Hexagonal BN (hBN) and cubic BN (cBN) are known as the representative crystal structures of BN. The former is chemically and thermally stable, and has been widely used as an electrical insulator and heat-resistant materials. The latter, which is a high-density phase, is an ultra-hard material second only to diamond. Recently, some progresses in the synthesis of high purity BN crystals were achieved by using Ba-BN as a solvent material at high pressure crystal growth [1]. Band-edge natures (cBN Eg=6.2eV and hBN Eg=6eV) were characterized by their optical properties. The key issue to obtain high purity crystals is to reduce oxygen and carbon contamination in the growth circumstances. It should be emphasized that hBN exhibits attractive potential for deep ultraviolet (DUV) light emitter [2 ] and also superior properties as substrate of graphene devices [3]. In this study, the effect of carbon impurity in BN is investigated. Three types of experimental approaches were carried out; (1) synthesis of high purity hBN single crystals and its characterization with respect to residual carbon, (2) high temperature solid state diffusion of carbon into hBN and its characterization, and (3) high temperature annealing of turbostratic B-C-N(t-BCN) compound under high pressure. t-BCN flakes obtained by chemical vapour deposition process was annealed near 3000C and 2GPa so as to become well crystallized.At annealing near 3000C at 2GPa with graphite, carbon incorporation of 1E21/cm3 in hBN was achieved with exhibiting totally different Cathode Luminescence spectra feature with high purity hBN crystals. Since major carbon contribution may affect the crystal structure of the 2-D layers stacking in hBN system, phase stability of BCN ternary phase will be introduced by the experimental results of high temperature annealing. Furthermore, effect of carbon impurity upon the synthesis of wurtzite BN from highly crystalline hBN via martensitic phase transformation will also be introduced.

Defect and Stress Reduction in High-Pressure and High-Temperature Synthetic Diamonds Using Gradient Cooling Technology

2020 ◽  
Vol 20 (5) ◽  
pp. 3358-3364 ◽  
Author(s):  
Ning Chen ◽  
Guoqing Zhang ◽  
Rui Li ◽  
Gang Xu ◽  
Fangbiao Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Stress Reduction ◽  
Synthetic Diamonds ◽  
Cooling Technology

Surface Structure of Large Synthetic Diamonds by High Temperature and High Pressure

2007 ◽  
Vol 24 (10) ◽  
pp. 2991-2993 ◽  
Author(s):  
Zang Chuan-Yi ◽  
Huang Guo-Feng ◽  
Ma Hong-An ◽  
Jia Xiao-Peng
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Surface Structure ◽  
Synthetic Diamonds

Synchrotron X-ray studies of strain in (100)-oriented high pressure-high temperature (HP-HT) synthetic diamonds

1996 ◽  
Vol 5 (11) ◽  
pp. 1254-1263 ◽  
Author(s):  
Grzegorz Kowalski ◽  
Moreton Moore ◽  
Gary Gledhill ◽  
Zoran Maričić
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
X Ray ◽  
Synthetic Diamonds ◽  
High Pressure High Temperature

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.

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