InSb Czochralski Growth Single Crystals for InGaSb Substrates

2014 ◽  
Vol 1616 ◽  
Author(s):  
J. E. Flores Mena ◽  
R. Castillo Ojeda ◽  
J. Díaz Reyes
Keyword(s):  
Low Cost ◽  
Electronic Devices ◽  
Czochralski Method ◽  
Liquid Nitrogen Temperature ◽  
Longitudinal Optical ◽  
Czochralski Growth ◽  
Etch Pit ◽  
Growth System ◽  
Radiation Sensors ◽  
Made In

ABSTRACTThe massive crystal growth of single crystal semiconductors materials has been of fundamental importance for the actual electronic devices industry. As a consequence of this one, we can obtain easily a large variety of low cost devices almost as made ones of silicon. Nowadays, the III-V semiconductors compounds and their alloys have been proved to be very important because of their optical properties and applications. It is the case of the elements In, Ga, As, Sb, which can be utilized for the fabrication of radiation sensors. In this work we present the results obtained from the ingots grown by the Czochralski method, using a growth system made in home. These results include anisotropic chemical attacks in order to reveal the crystallographic orientation and the possible polycrystallinity. Isotropic chemical attacks were made to evaluate the etch pit density. Metallographic pictures of the chemical attacks are presented in this work. Among the results of these measurements, the best samples presented in this work showed mobilities of 62.000 cm2/V*s at room temperature and 99.000 cm2/V*s at liquid nitrogen temperature. Typical pit density was 10,000/cm2. The Raman spectra present two dominant peaks associated at Transversal Optical (TO)- and Longitudinal Optical (LO)-InSb, the first vibrational mode is dominant due to the crystalline direction of the ingots and second one is associated to high defects density.

scholarly journals Effect of Internal Radiation on Process Parameters in the Global Simulation of Growing Large-Size Bulk β-Ga2O3 Single Crystals with the Czochralski Method

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 763
Author(s):  
Xia Tang ◽  
Botao Liu ◽  
Yue Yu ◽  
Botao Song ◽  
Pengfei Han ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Single Crystal ◽  
Process Parameters ◽  
Czochralski Method ◽  
Surface Radiation ◽  
Czochralski Growth ◽  
Internal Radiation ◽  
System A ◽  
Large Size ◽  
Growth System

As a crystal grows, the temperature distribution of the crystal and melt will change. It is necessary to study the dynamic process of single-crystal growth. Due to the relatively low crystallization rates used in the industrial Czochralski growth system, a steady state is used to compute the temperature distribution and melt flow. A two-dimensional axisymmetric model of the whole Czochralski furnace was established. The dynamic growth process of large-size bulk β-Ga2O3 single crystal using the Czochralski method has been numerically analyzed with the parameter sweep method. In this paper, two cases of internal radiation and no internal radiation were compared to study the effect of radiation on the process parameters. The temperature distribution of the furnace, the temperature field, and the flow field of the melt was calculated. The temperature, the temperature gradient of the crystal, the temperature at the bottom of the crucible, and the heater power were studied for the crystals grown in the two cases of radiation. The results obtained in this study clearly show that the loss calculated by including the internal radiation is higher compared to that including the surface radiation.

Response fitting in low-cost radiation sensors

2010 ◽  
Vol 1 (08) ◽  
pp. 920-925
Author(s):  
A. Gómez Moreno ◽  
P.J. Casanova Peláez ◽  
F.A. Díaz Garrido ◽  
J.M. Palomar Carnicero ◽  
R. López García ◽  
...  
Keyword(s):  
Low Cost ◽  
Fitting In ◽  
Radiation Sensors

scholarly journals Bimetallic Ni-Based Catalysts for CO2 Methanation: A Review

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Anastasios I. Tsiotsias ◽  
Nikolaos D. Charisiou ◽  
Ioannis V. Yentekakis ◽  
Maria A. Goula
Keyword(s):  
Low Temperature ◽  
Noble Metals ◽  
Recent Progress ◽  
Low Cost ◽  
Alloy Formation ◽  
Co2 Methanation ◽  
High Performing ◽  
Mobile Sources ◽  
Low Dispersion ◽  
Made In

CO2 methanation has recently emerged as a process that targets the reduction in anthropogenic CO2 emissions, via the conversion of CO2 captured from point and mobile sources, as well as H2 produced from renewables into CH4. Ni, among the early transition metals, as well as Ru and Rh, among the noble metals, have been known to be among the most active methanation catalysts, with Ni being favoured due to its low cost and high natural abundance. However, insufficient low-temperature activity, low dispersion and reducibility, as well as nanoparticle sintering are some of the main drawbacks when using Ni-based catalysts. Such problems can be partly overcome via the introduction of a second transition metal (e.g., Fe, Co) or a noble metal (e.g., Ru, Rh, Pt, Pd and Re) in Ni-based catalysts. Through Ni-M alloy formation, or the intricate synergy between two adjacent metallic phases, new high-performing and low-cost methanation catalysts can be obtained. This review summarizes and critically discusses recent progress made in the field of bimetallic Ni-M (M = Fe, Co, Cu, Ru, Rh, Pt, Pd, Re)-based catalyst development for the CO2 methanation reaction.

scholarly journals Extraction of γ-Alumina from Low-Cost Kaolin

Resources ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 63
Author(s):  
Khalil Ibrahim ◽  
Mohammad Moumani ◽  
Salsabeela Mohammad
Keyword(s):  
Low Cost ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aluminum Metal ◽  
Alumina Particles ◽  
Two Stages ◽  
Method Of Extraction ◽  
Microcrystalline Powder ◽  
Made In

A combined process is proposed for the utilization of local kaolin to produce alumina particles. The applied process is made in two stages: calcination at 700 °C with sodium chloride and leaching with sulfuric followed by hydrochloric acids. The optimal extraction efficiency can be obtained when the conditions are as follows: leaching temperature is at 140 °C, leaching time is 3 h 45 min and concentration of sulfuric acid is 40 wt.%. The results show that the purity of alumina reaches 79.28%, which is suitable for the production of aluminum metal. It is evident that this method of extraction of alumina from the kaolin ash is practical and feasible. The structural and morphological properties of the calcined microcrystalline powder was characterized by X-ray diffraction and scanning electron microscope (SEM).

scholarly journals Czochralski growth and spectroscopic investigations of Yb3+, La3+:Na2SO4(I) and Nd3+:Na2SO4(I)

1999 ◽  
Vol 14 (10) ◽  
pp. 4093-4097 ◽  
Author(s):  
Patric Mikhail ◽  
Reto Basler ◽  
Jürg Hulliger
Keyword(s):  
Cross Sections ◽  
Inductively Coupled Plasma ◽  
Stimulated Raman Scattering ◽  
Optical Emission ◽  
Czochralski Method ◽  
Distribution Coefficients ◽  
Czochralski Growth ◽  
Inductively Coupled ◽  
Spectroscopic Investigations ◽  
New Material

Ln3+-stabilized Na2SO4 (phase I) single crystals were grown by the Czochralski method. Differential thermal analysis revealed the influence of the ionic radius of Ln3+ on the stabilization of Na2SO4(I). Distribution coefficients (∼0.8–1.1) were measured by the inductively coupled plasma optical emission spectroscopy method and x-ray fluorescence spectroscopy. Spectroscopic investigations yielded absorption cross sections of 0.6 × 10−20 cm2 (π-polarized, 928.5 nm) and 1.5 × 10−20 cm2 (π-polarized, 797.3 nm) for Yb3+, La3+:Na2SO4 and Nd3+:Na2SO4, respectively. Crystal growth of Gd3+-stabilized Na2SO4(I) provides an interesting new material for stimulated Raman scattering experiments.

scholarly journals A secondary stage design for the preparation of microfossils for the SEM

1993 ◽  
Vol 12 (2) ◽  
pp. 154-154
Author(s):  
Stephen Tatman
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Low Cost ◽  
Sample Tube ◽  
Stage Design ◽  
Single Carrier ◽  
Secondary Stage ◽  
Scanning Electron ◽  
Made In

Abstract. The preparation of microfossil specimens for study with the scanning electron microscope involves the transfer of material from slides to stubs. Specimens must then be oriented and mounted securely. To do this accurately the slide and stub should both be viewed through a stereomicroscope. However due to differences in shape and height, both surfaces are not usually in the plane of focus at the same time. Many micropalaeontologists routinely use small boxes or sample tube lids to hold the stub and refocus before finally mounting the specimens. The risk of dropping specimens is reduced by using a single carrier, securely holding both the slide and stub. The design illustrated below (fig.1) was developed from a prototype constructed from cardboard and plastic. The metal unit can easily be made in a workshop at a very low cost or cardboard versions made in the laboratory.The stage is based on the principle that both slide and stub should be held securely, close together and in the same plane of focus. The slide holders should be secure but not too tight otherwise the stub may be jarred as slides are changed. The number of slides which can be held on one unit may be varied. The presence of two holders has proved useful, any more could make the unit cumbersome. If the microscope to be used does not have a wide stage then it may prove more practical to have only one holder.The stub holders allow the stub to be clamped to . . .

scholarly journals Impact of the COVID-19 pandemic on electrophysiological procedures at a national referral center

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
A Cueva-Parra ◽  
G Munoz-Benavides ◽  
W Ortiz-Solis ◽  
J Gomez-Flores ◽  
MF Marquez ◽  
...  
Keyword(s):  
Electronic Devices ◽  
Referral Center ◽  
Funding Sources ◽  
Cardiac Implantable Electronic Devices ◽  
Electrophysiological Studies ◽  
Electrophysiological Procedures ◽  
The Impact ◽  
Large Groups ◽  
Made In ◽  
Funding Acknowledgements

Abstract Funding Acknowledgements Type of funding sources: None. Background - Introduction: The COVID-19 pandemic has generated serious repercussions on the health system, reducing the number of all cardiology procedures worldwide. Objectives Describe the impact of the COVID-19 pandemic on the procedures performed by the electrophysiology department in a national referral center.  Methods We made a retrospective review of our data base and we compared procedures made in the last 3 years since 2017 to 2019 with the procedures made in the 2020. We divide the procedures into two large groups: Cardiac Implantable Electronic Devices (CIED) related procedures (which included implants, revisions, changes, upgrades and extractions) and electrophysiological studies and ablations (which included conventional and complex procedures). Other types of procedures were no included. Results There was a significant reduction in all procedures, the average of procedures performed in the last 3 previous years was 467 (there were 479 in 2017, 411 in 2018 and 511 in 2019), while in 2020 we performed only 319 (p = 0.01); this represents a reduction of 33.4% in the total number of procedures performed in our center. There was no statistical difference regarding the CIED related procedures, the average of procedures of the last 3 previous years was 174 (there were 186 in 2017, 148 in 2018 and 188 in 2019), and in 2020 we performed 189 procedures, this value is near to the average of the last 3 previous years and very close to the value of the 2019 (p = 0.46). Regarding the electrophysiological studies and ablations, the average of procedures of the last 3 previous years was 293 (there were 293 in 2017, 263 in 2018 and 323 in 2019), while in 2020 we performed only 129 procedures, considerably decreasing compared to the previous years (p < 0.01). The reduction in the electrophysiological studies and ablations was 55.97%. The most affected months were April, May and June. Conclusions The COVID-19 pandemic considerably affected the number of electrophysiological procedures in our center, reducing it by 33.4% compared to the previous years. The reduction of procedures fundamentally affected the electrophysiological studies and ablations, reducing them by 55.97%. The number of CIED related procedures were no affected. Electrophysiological procedures Procedures2017201820192017-2019 average2020CIED related procedures186148188174189Electrophysiological studies and ablations293263323293129Total479411511467319Comparative table of the electrophysiological procedures performed in our center in recent years.Abstract Figure. Comparison of the procedures.

scholarly journals Photogrammetry-based Texture Analysis of a Volcaniclastic Outcrop-peel: Low-cost Alternative to TLS and Automation Potentialities using Haar Wavelet and Spatial-Analysis Algorithms

2017 ◽  
Vol 31 (1) ◽  
pp. 16-27 ◽  
Author(s):  
Christopher Gomez ◽  
Kyoko Kataoka ◽  
Aditya Saputra ◽  
Patrick Wassmer ◽  
Atsushi Urabe ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Wavelet Decomposition ◽  
Low Cost ◽  
Decomposition Analysis ◽  
Haar Wavelet ◽  
Present Contribution ◽  
Close Range Photogrammetry ◽  
Original Goal ◽  
Close Range ◽  
Made In

Numerous progress has been made in the field of applied photogrammetry in the last decade, including the usage of close-range photogrammetry as a mean of conservation and record of outcrops. In the present contribution, we use the SfM-MVS method combined with a wavelet decomposition analysis of the surface, in order to relate it to morphological and surface roughness data. The results demonstrated that wavelet decomposition and RMS could provide a rapid insight on the location of coarser materials and individual outliers, while arithmetic surface roughness were more useful to detect units or layers that are similar on the outcrop. The method also emphasizes the fact that the automation of the process does not allows clear distinction between any artefact crack or surface change and that human supervision is still essential despite the original goal of automating the outcrop surface analysis.

scholarly journals The Rise of the OM-LoC: Opto-Microfluidic Enabled Lab-on-Chip

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1467
Author(s):  
Harry Dawson ◽  
Jinane Elias ◽  
Pascal Etienne ◽  
Sylvie Calas-Etienne
Keyword(s):  
Low Cost ◽  
Optical Components ◽  
New Era ◽  
Lab On Chip ◽  
Highly Sensitive ◽  
Multiple Challenges ◽  
On Chip ◽  
Optical Circuits ◽  
Made In

The integration of optical circuits with microfluidic lab-on-chip (LoC) devices has resulted in a new era of potential in terms of both sample manipulation and detection at the micro-scale. On-chip optical components increase both control and analytical capabilities while reducing reliance on expensive laboratory photonic equipment that has limited microfluidic development. Notably, in-situ LoC devices for bio-chemical applications such as diagnostics and environmental monitoring could provide great value as low-cost, portable and highly sensitive systems. Multiple challenges remain however due to the complexity involved with combining photonics with micro-fabricated systems. Here, we aim to highlight the progress that optical on-chip systems have made in recent years regarding the main LoC applications: (1) sample manipulation and (2) detection. At the same time, we aim to address the constraints that limit industrial scaling of this technology. Through evaluating various fabrication methods, material choices and novel approaches of optic and fluidic integration, we aim to illustrate how optic-enabled LoC approaches are providing new possibilities for both sample analysis and manipulation.

Sign in / Sign up

Export Citation Format

Share Document