Study of the Spontaneous Nucleation of 3C-SiC Single Crystals Using CF-PVT Technique

2010 ◽  
Vol 645-648 ◽  
pp. 55-58 ◽  
Author(s):  
Irina G. Galben-Sandulache ◽  
Guoli L. Sun ◽  
Jean Marc Dedulle ◽  
Thierry Ouisse ◽  
Roland Madar ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Future Development ◽  
Critical Issue ◽  
Structural Quality ◽  
Czochralski Growth ◽  
High Quality ◽  
Spontaneous Nucleation ◽  
Bulk Growth ◽  
Very High

The control of the nucleation step is a critical issue for a future development of 3C-SiC bulk growth. The possibility to get very high quality 3C-SiC single crystal through self-nucleation on graphite was already demonstrated but the large number of nuclei limits the growth of only one crystal. In this study, we have investigated different configurations that help improving the nucleation step. For that, the “necking” stage, well established in Bridgman or Czochralski growth processes, has been successfully applied to the growth of 3C-SiC with the CF-PVT technique. This has allowed getting only one 3C-SiC crystal. The enlarged parts, after having passed the neck, are of high structural quality.

Growth and Characterization of Single Crystal Epitaxial CoGa on MBE Grown III-V Semiconductors

1988 ◽  
Vol 144 ◽  
Author(s):  
K. C. Garrison ◽  
C. J. Palmstrøm ◽  
R. A. Bartynski
Keyword(s):  
Substrate Temperature ◽  
Single Crystal ◽  
Single Crystals ◽  
Structural Quality ◽  
High Quality ◽  
Auger Analysis ◽  
Post Deposition

ABSTRACTWe have demonstrated growth of high quality single crystal CoGa films on Ga1−xAlxAs. These films were fabricated in-situ by codeposition of Co and Ga on MBE grown Ga1−xAlxAs(100) surfaces. The elemental composition of the films was determined using Rutherford Backscattering (RBS) and in-situ Auger analysis. The structural quality of the films' surfaces was studied using RHEED (during deposition) and LEED (post deposition). RBS channeling was used to determine the bulk crystalline quality of these films.For ∼500 Å CoGa films grown at ∼450°C substrate temperature, channeling data showed good quality epitaxial single crystals [χmin ∼7%] with minimal dechanneling at the interface.

Comparative Study of Differently Grown 3C-SiC Single Crystals with Birefringence Microscopy

2008 ◽  
Vol 600-603 ◽  
pp. 71-74 ◽  
Author(s):  
Didier Chaussende ◽  
Frédéric Mercier ◽  
Roland Madar ◽  
Michel Pons
Keyword(s):  
High Temperature ◽  
Comparative Study ◽  
Single Crystals ◽  
Growth Conditions ◽  
High Rate ◽  
High Quality ◽  
Bulk Growth ◽  
Stable Growth ◽  
Very High

We have investigated through birefringence microscopy, a set of 3C-SiC crystals grown with the CF-PVT process, starting from different seeds and under different growth conditions. Through self nucleation experiments, the stable growth of very high quality 3C-SiC crystals at high temperature (2100°C) and at high rate (roughly 0.2 mm/h) is demonstrated. The possibility to develop bulk growth of 3C-SiC crystals is discussed.

Nucleation and Growth of 3C-SiC Single Crystals from the Vapor Phase

2009 ◽  
Vol 615-617 ◽  
pp. 31-36 ◽  
Author(s):  
Didier Chaussende ◽  
Jessica Eid ◽  
Frédéric Mercier ◽  
Roland Madar ◽  
Michel Pons
Keyword(s):  
Single Crystals ◽  
Vapor Phase ◽  
Future Development ◽  
Growth Process ◽  
Nucleation And Growth ◽  
Structural Quality ◽  
Bulk Growth ◽  
Nucleation Growth

The conditions to succeed in growing 3C-SiC single crystals are first, make available large 3C-SiC seeds and second, develop a suitable growth process. In this paper, we will address those two issues by reviewing the most recent results in the field. Nucleation, growth, structural quality and doping results will be presented. New insights on 3C bulk growth will be discussed with respect to a future development of real bulk 3C-SiC ingots.

Two-dimensional (PEA)2PbBr4 perovskite single crystals for a high performance UV-detector

2019 ◽  
Vol 7 (6) ◽  
pp. 1584-1591 ◽  
Author(s):  
Yunxia Zhang ◽  
Yucheng Liu ◽  
Zhuo Xu ◽  
Haochen Ye ◽  
Qingxian Li ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
High Performance ◽  
Two Dimensional ◽  
Uv Detector ◽  
High Quality ◽  
Photo Response ◽  
Response Performance

A centimeter-sized high-quality two-dimensional (PEA)2PbBr4 single crystal was prepared, which exhibited superior UV photo-response performance.

scholarly journals Simulation and Experiment for Growth of High-Quality and Large-Size AlN Seed Crystals by Spontaneous Nucleation

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3939
Author(s):  
Zuoyan Qin ◽  
Wenhao Chen ◽  
Danxia Deng ◽  
Zhenhua Sun ◽  
Baikui Li ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Single Crystal ◽  
Growth Surface ◽  
Inversion Method ◽  
High Quality ◽  
Radial Temperature ◽  
Heater Power ◽  
Seed Crystals ◽  
Spontaneous Nucleation ◽  
Large Size

Seed crystals are the prerequisite for the growth of high quality and large size aluminum nitride (AlN) single crystal boules. The physical vapor transport (PVT) method is adopted to grow AlN seed crystal. However, this method is not available in nature. Herein, the temperature field distribution in the PVT furnace was simulated using the numerical analysis method to obtain free-standing and large-size seeds. The theoretical studies indicate that the temperature distribution in the crucible is related to the crucible height. According to the theory of growth dynamics and growth surface dynamics, the optimal thermal distribution was achieved through the design of a specific crucible structure, which is determined by the ratio of top-heater power to main-heater power. Moreover, in our experiment, a sole AlN single crystal seed with a length of 12 mm was obtained on the tungsten (W) substrate. The low axial temperature gradient between material source and substrate can decrease the nucleation rate and growth rate, and the high radial temperature gradient of the substrate can promote the expansion of crystal size. Additionally, the crystallinity of the crystals grown under different thermal field conditions are analyzed and compared. The Raman results manifest the superiority of the thermal inversion method in the growth of high quality AlN single crystal.

Successive Magnetic Transitions on Single Crystal Cu3(OH)4SO4

2011 ◽  
Vol 170 ◽  
pp. 194-197
Author(s):  
Shigeo Hara ◽  
Hirohiko Sato
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Single Crystals ◽  
Field Dependence ◽  
Easy Axis ◽  
The Other ◽  
Magnetic Transitions ◽  
Copper Hydroxide ◽  
High Quality ◽  
Measured Field

Cu3(OH)4SO4, a parallel Cu (S = 1/2) triple chain system, is an interesting magnet because an idle-spin state is expected on the central chain. We have succeeded in growing high-quality single crystals of Cu3SO4(OH)4 by a hydrothermal method from copper sulfate and copper hydroxide. We measured field dependence of the magnetization on a single crystal under various directions of magnetic field up to 7 T. We found a clear magnetic anisotropy and confirmed that the existence of the easy axis lies in the ac plane. Under magnetic fields parallel to the c-axis and the a-axis at 2.5 K, we observed field-induced successive magnetic transitions. In the case of B//c, two anomalies of the magnetization are observed at 0.9 and 1.7 T, On the other hand, there are broad anomalies in the magnetization at 3.7 and 5.6 T in the case of B//a.

Characterisation of Defects in ZnO Implanted by Hydrogen

2015 ◽  
Vol 365 ◽  
pp. 49-54
Author(s):  
Ivan Procházka ◽  
Jakub Čížek ◽  
Jan Valenta ◽  
Vladimír Havránek ◽  
Petr Hruška ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Positron Annihilation ◽  
Optical Activity ◽  
Optical Transmittance ◽  
Hydrogen Impurity ◽  
High Quality ◽  
Positron Annihilation Lifetime ◽  
Zno Single Crystal

In the present work, defects created by implantation of hydrothermally grown ZnO single crystals of high quality with H+ions were investigated by positron annihilation lifetime (LT) spectroscopy combined with measurements of optical transmittance (OT) and photoluminescence (PL). First, zinc vacancies attached with one hydrogen impurity (VZn– 1H) atom were identified in the virgin ZnO single crystal. The ZnO single crystals were then bombarded by H+ions with the energy of 2.5 MeV to the fluence of 1016cm-2. It was found that VZn– VOdivacancies were introduced into ZnO by H+-implantation. Effects of H+-implantation on the optical activity of defects in ZnO lattice are characterised in the light of the present OT and PL data.

scholarly journals Single crystal diffraction at high energy and high pressure on I15 at DLS

2014 ◽  
Vol 70 (a1) ◽  
pp. C402-C402
Author(s):  
Nicola Casati ◽  
Annette Kleppe ◽  
Fabrizio Nestola ◽  
Heribert Wilhelm
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
High Energy ◽  
Quality Data ◽  
Extreme Condition ◽  
X Rays ◽  
Ambient Conditions ◽  
Single Crystal Diffraction ◽  
Natural Diamonds ◽  
Very High

The Extreme Condition beamline (I15) at the Diamond Light Source is a dedicated beamline for powder as well as single crystal diffraction on samples at extreme conditions in pressure or temperature. Single crystal data on either pressurized samples in a diamond anvil cell (DAC) or at ambient conditions are routinely done on a diffractometer scanning φ and ω using X-rays with energies in the range from 20 keV to 80 keV. Depending on the sample beam sizes varying from 20 μm to several 100 μm can be used. Data are recorded with an Atlas CCD (Agilent Technologies) and then treated with the Crysalis software package. In this contribution we highlight the very high accuracy of single-crystals data obtainable at I15 on two examples of single crystals in a DAC (E = 40 keV) and a sample at ambient conditions (E = 60 keV). A single crystal of the binary transition metal compound FeGe (B20 structure, space group P213, Z=4) was studied up to 11 GPa to determine the evolution of the inter-atomic distances (both atoms occupy the 4a Wyckoff positions). More than 200 unique data could be used to refine 7 parameters with an average R1 on all data of ~7%. Very high quality data have also been obtained for single crystals from the field of chemical crystallography, for which not only connectivity but also small bonding features can be detected. For example in l,6;8,13 biscarbonyl[14]annulene the progressive loss of aromatic character could be monitored and, in a special setup, the data allowed for the refinement of an unconstrained multipolar model. The use of 60 keV photons was crucial for an experiment on natural diamonds containing a variety of inclusions. At these energies the absorption of the diamond can be neglected. The aim of the study was to obtain information on possible recurrent crystallographic relationships between the inclusions and the diamond host on a significant number of extremely rare natural diamonds containing minerals.

scholarly journals Resistivity and piezoelectric properties of Ca3TaGa1.5Al1.5Si2O14 single crystals for high temperature sensors

RSC Advances ◽  
2017 ◽  
Vol 7 (89) ◽  
pp. 56697-56703 ◽  
Author(s):  
Xiuwei Fu ◽  
Encarnación G. Víllora ◽  
Yoshitaka Matsushita ◽  
Yuuki Kitanaka ◽  
Yuji Noguchi ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Single Crystals ◽  
Temperature Sensor ◽  
Piezoelectric Properties ◽  
Temperature Sensors ◽  
High Quality ◽  
Sensor Applications ◽  
High Temperature Sensor

A high quality CTGAS single crystal with excellent properties for high temperature sensor applications.

scholarly journals Organic Molecule Assisted Growth of Perovskite Films Consisting of Square Grains by Surface-Confined Process

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 473
Author(s):  
Shao Xin Yan ◽  
Chang Bao Han ◽  
Jianhua Huang ◽  
Yichuan Chen ◽  
Xiaobo Zhang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Organic Molecule ◽  
Lateral Growth ◽  
High Quality ◽  
Grain Number ◽  
Confined Spaces ◽  
Single Crystal Films ◽  
Crystal Films ◽  
Pl Emission

Organic–inorganic perovskite single crystals are promising in the field of optoelectronics due to their excellent optoelectronic properties. However, the ion transport of perovskite precursor is poor in confined spaces, which results in difficulty in the preparation of perovskite single-crystal films. Herein, MAPbBr3 films consisting of square grains were fabricated by the surface-confined process using the organic molecule PEAI (phenethylammonium iodide). Under the effect of oversaturation gradient, PEA+ is combined with the surface of perovskite grain from top to side, which constrains the lateral growth of grains and induces a downward growth of perovskite, leading to the formation of square grains. With the improvement of concentration PEAI, the perovskite film exhibits a decreased side length of grains (from 0.98 to 12.96 μm) and increased grain number and coverage, as well as crystallinity. The perovskite single crystalline grain films with PEAI showed double photoluminescence (PL) emission peaks due to the existence of iodine-rich perovskite. This work may provide a practical way to fabricate high-quality perovskite films for perovskite photoelectronic devices.

Sign in / Sign up

Export Citation Format

Share Document