Gan Nanowire Growth by Thermal Evaporation Method

2012 ◽  
Vol 501 ◽  
pp. 276-280
Author(s):  
Leila Shekari ◽  
Abu Hassan Haslan ◽  
Hassan Zainuriah
Keyword(s):  
Gas Flow ◽  
Thermal Evaporation ◽  
Mixed Gas ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Transmission Electron ◽  
Gas Atmosphere ◽  
Ar Gas ◽  
Uniform Diameter ◽  
Different Diameters

In this research we introduce an inexpensive method to produce highly crystalline GaN Nanowires (NWs) grown on porous zinc oxide (PZnO) using commercial GaN powder, either in argon gas or combination of nitrogen and Ar gas atmosphere, by thermal evaporation. Morphological structural studies using transmission electron microscope (TEM) and scanning electron microscopy (SEM) measurements showed the role of porosity and different gas flowing, in the alignment and nucleation of these NWs. The NWs grown under flow of mix gases have very different diameters of between 50 and 200 nm, but those which were grown in Ar gas atmosphere, have rather uniform diameter of around 50 nm. The length of the GaN NWs was uniform, (around 10 µm). Optical and structural characterizations were performed by energy-dispersive X-ray spectroscopy (EDX) and high resolution X-ray diffraction (HR-XRD). Results revealed that these NWs are of single-crystal hexagonal GaN with [oooı] and [ıoīı] growth directions for the NWs grown under Ar and mixed gas flow.

Fabrication and Structural and Optical Characterizations of GaN Nano and Micro Structures Grown by Thermal Evaporation Method

2012 ◽  
Vol 545 ◽  
pp. 88-92
Author(s):  
Leila Shekari ◽  
Abu Hassan Haslan ◽  
Hassan Zainuriah
Keyword(s):  
Thermal Evaporation ◽  
Lattice Mismatch ◽  
Thermal Evaporation Method ◽  
Evaporation Method ◽  
Ceramic Boat ◽  
Gas Atmosphere ◽  
Ar Gas ◽  
Micro Structures

Abstract. Gallium Nitride (GaN) nano and micro structures were grown on different substrates, such as ceramic boat and alumina plate using thermal evaporation method with commercial GaN powder under the flow of Argon (Ar) gas atmosphere. Micro structural studies by scanning electron microscopy (SEM) revealed the role of different substrates in the nucleation of the GaN nano and micro wires and ribbons. Additional structural and optical characterizations were performed using energy-dispersive X-ray spectroscopy (EDX) and photoluminescence (PL) spectroscopy. Results indicated that the nanowires and nanoribbons are of single-crystal hexagonal GaN and are more and less orderly in their growth with different substrates. The quality of growth of the GaN nanowires and nanoribbons for different substrates is highly dependent on the lattice mismatch between the nanowires and their substrates and it also depends on the conditions of the growth.

Heteroe-Pitaxial Growth and Optical Properties of SnO2 Nanowires on ZnS Nanobelts

2012 ◽  
Vol 535-537 ◽  
pp. 481-485 ◽  
Author(s):  
Mang Jiang ◽  
Jun Hong Duan ◽  
Zhiang Liu
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Structural Information ◽  
X Ray Diffraction ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

The authors present the results of hetero-epitaxial growth of ultrafine SnO2nanowires on ZnS nanobelt substrates by a simple thermal evaporation method. ZnS/SnO2hetero-nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), transmission electron microscopy (TEM) to obtain the morphology and structural information. Comparing with ZnS nanobelts and SnO2nanowires respectively, the optical properties of ZnS/SnO2hetero-nanostructures are studied by Raman scattering and photoluminescence (PL) spectroscopy at room temperature.

ZnS nanowires growth on two different types of substrate using simple thermal evaporation method

2020 ◽  
Vol 34 (26) ◽  
pp. 2050231
Author(s):  
B. Abadllah ◽  
M. Kakhia ◽  
A. Obaide ◽  
W. Zetoun
Keyword(s):  
Electron Microscopy ◽  
Thermal Evaporation ◽  
Sem Images ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Evaporation Method ◽  
Main Compound ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Transmission Electron

ZnS nanowires films were grown on two different substrates silicon and glass, with PbS dopant at 5 wt.%, using thermal evaporation method. The silicon is single crystal (only Si), while the glass is as amorphous substrate (mainly SiO2). In the used substrates, the morphology was confirmed by Atomic Force Microscopy (AFM) as well as Scanning Electron Microscopy (SEM) images (cross-section and surface). High Resolution Transmission Electron Microscopy (HRTEM) has been used to confirm the ZnO nanowires for doped films (PbS:ZnS) in both silicon and glass substrates, with diameter less than 50 nm and the thickness was varied from 2000 nm to 3000 nm. The undoped film has dense structure and is thin with thickness of 200 nm. The growth of nanowires is not affected by the two substrate types (silicon and glass). The compositions of chemical films have been verified by energy dispersive X-ray spectroscopy (EDX), and it confirms that ZnS is the main compound. X-ray Diffraction (XRD) investigated the crystallographic properties with wurtzite structure. Optical properties (transparency and bandgap) were deduced from UltraViolet Visible (UV-Vis) spectra of ZnS films (PbS 0 and 5 wt.%) deposited on glass substrate. Raman, Photoluminescence (PL) and Fourier transform infrared (FTIR) techniques confirm ZnS composition and its nonstructural growth. Finally, a good agreement between the XRD, FTIR and HRTEM analyses was found.

High Purity Magnetite Microparticles Directly Derived from Mill Scale via Hydrogen-Reduction Method

2021 ◽  
Vol 1016 ◽  
pp. 286-291
Author(s):  
Autchariya Boontanom ◽  
Piyada Suwanpinij
Keyword(s):  
Flow Rate ◽  
High Purity ◽  
Gas Flow ◽  
Reduction Method ◽  
Hydrogen Reduction ◽  
Reduction Temperature ◽  
Mixed Gas ◽  
Mill Scale ◽  
X Ray ◽  
Ar Gas

This study develops a fast and simple way to produce high purity magnetite (Fe3O4) microparticles from mill scale by using hydrogen reduction with the addition of vapour as a retarding agent. By optimising the reduction temperature and gas flow rate, the characterisations by X-ray diffractometry technique shown that the Fe3O4 fraction of over 93 wt.-% is shown at the reduction temperature of 550 – 650 oC with the flow rate of the 4.5-5.5 mol%H2 + Ar gas + H2O gas mixture from 100 – 200 ml/min. The highest Fe3O4 fraction of over 99 wt.-% can be achieved from the reduction with the mixed gas at 650 oC and the flow rate of 200 ml/min for 4 hour.

Synthesis of Chainlike In2Ge2O7/Amorphous GeO2 Core/Shell Nanocables and Their Luminescence

2007 ◽  
Vol 7 (12) ◽  
pp. 4365-4368 ◽  
Author(s):  
Yong Su ◽  
Xia Meng ◽  
Sen Li ◽  
Yiqing Chen ◽  
Liang Xu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Growth Process ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Core Shell ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Transmission Electron ◽  
Spectroscopy Studies

Novel chainlike In2Ge2O7/amorphous GeO2 core/shell nanocables were successfully synthesized by the simple thermal evaporation method without the presence of catalyst. The growth process of the nanocables is based on vapor–solid (VS) growth mechanism. Its morphology and microstructures were characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and photoluminescence spectroscopy. Studies indicate that typical chainlike nanocables consist of single crystalline In2Ge2O7 nanowires (core) with diameter of about 30 nm and amorphous GeO2 chainlike nanostructures (shell). Four emission peaks, namely 401 nm, 448.5 nm, 466.5 nm, and 491 nm, were observed in the room-temperature photoluminescence measurements.

Electron Microscopy/Diffraction Study of the Ternary Mn-Er-S System

1990 ◽  
Vol 48 (1) ◽  
pp. 76-77
Author(s):  
A. R. Landa Canovas ◽  
L.C. Otero Diaz ◽  
T. White ◽  
B.G. Hyde
Keyword(s):  
Electron Microscopy ◽  
Gas Flow ◽  
Graphite Crucible ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Alumina Crucible ◽  
X Ray ◽  
Intermediate Phases ◽  
Twin Band ◽  
Ar Gas

X-Ray diffraction revealed two intermediate phases in the system MnS+Er2S3,:MnEr2S4= MnS.Er2S3, and MnEr4S7= MnS.2Er2S3. Their structures may be described as NaCl type, chemically twinned at the unit cell level, and isostructural with CaTi2O4, and Y5S7 respectively; i.e. {l13} NaCl twin band widths are (4,4) and (4,3).The present study was to search for structurally-related (twinned B.) structures and or possible disorder, using the more sensitive and appropiate technigue of electron microscopy/diffraction.A sample with nominal composition MnEr2S4 was made by heating Mn3O4 and Er2O3 in a graphite crucible and a 5% H2S in Ar gas flow at 1500°C for 4 hours. A small amount of this material was thenannealed, in an alumina crucible, contained in sealed evacuated silica tube, for 24 days at 1100°C. Both samples were studied by X-ray powder diffraction, and in JEOL 2000 FX and 4000 EX microscopes.

X- ray diffraction and dielectric properties of PbSe thin films

2019 ◽  
Vol 15 (34) ◽  
pp. 1-14
Author(s):  
Bushra A. Hasan
Keyword(s):  
Thin Films ◽  
Thermal Activation ◽  
Thermal Evaporation ◽  
Thermal Activation Energy ◽  
Dielectric Constants ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Glass Substrates

Lead selenide PbSe thin films of different thicknesses (300, 500, and 700 nm) were deposited under vacuum using thermal evaporation method on glass substrates. X-ray diffraction measurements showed that increasing of thickness lead to well crystallize the prepared samples, such that the crystallite size increases while the dislocation density decreases with thickness increasing. A.C conductivity, dielectric constants, and loss tangent are studied as function to thickness, frequency (10kHz-10MHz) and temperatures (293K-493K). The conductivity measurements confirm confirmed that hopping is the mechanism responsible for the conduction process. Increasing of thickness decreases the thermal activation energy estimated from Arhinus equation is found to decrease with thickness increasing. The increase of thickness lead to reduce the polarizability α while the increasing of temperature lead to increase α.

Effects of Surface Energy on the Microstructures of Thin Sb Films

1990 ◽  
Vol 202 ◽  
Author(s):  
L. H. Chou ◽  
M. C. Kuo
Keyword(s):  
Electron Microscopy ◽  
Surface Energy ◽  
Grain Growth ◽  
Grain Orientation ◽  
Thermal Evaporation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Transmission Electron ◽  
Diffraction Peaks

ABSTRACTThin Sb films have been prepared on glass substrates by rapid thermal evaporation. Films with thicknesses varied from 260 Å to 1300Å were used for the study. X-ray diffraction data showed that for films deposited at room substrate temperature, an almost random grain orientation was observed for films of 1300 Å thick and a tendency for preferred grain orientation was observed as films got thinner. For films of 260 Å thick, only two x-ray diffraction peaks--(003) and (006) were observed. After thermal annealing, secondary grains grew to show preferred orientation in all the films. This phenomenon was explained by surface-energy-driven secondary grain growth. This paper reports the effects of annealing time and film thickness on the secondary grain growth and the evolution of thin Sb film microstmctures. Transmission electron microscopy (TEM) and x-ray diffraction were used to characterize the films.

PREPARATION, CHARACTERIZATION AND LUMINESCENCE PROPERTIES OF Eu DOPED CaAl2O4 NANOCONES

2013 ◽  
Vol 27 (19) ◽  
pp. 1341018 ◽  
Author(s):  
J. M. LIANG ◽  
L. L. HE ◽  
Z. Q. SHEN ◽  
D. L. ZHANG
Keyword(s):  
Electron Microscope ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
The Body ◽  
Monoclinic Structure ◽  
Thermal Evaporation Method ◽  
Room Temperature Photoluminescence ◽  
Spectrum Measurement ◽  
Transmission Electron ◽  
First Time

Europium doped CaAl 2 O 4 nanocones have been grown first time by thermal evaporation method. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to analyze the morphology, size and crystal structure of the nanocones. The body of the nanocones are about 2–20 μm in length and their diameters are 200 nm to 1 μm at one end and tapers off to a ~ 40–200 nm at the tip end. The as-synthesized nanocones are single crystalline in monoclinic structure and grow along the [010] direction and the normal direction of (100) and (001). The room temperature photoluminescence (PL) and cathodoluminescence (CL) spectrum measurement reveals that CaAl 2 O 4: Eu 2+ nanocones emit light at about 440 nm.

scholarly journals Compositional Dependence of Structural Properties of Prepared Alloys and Films

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
M. F. A. Alias ◽  
A. A. J. Al-Douri ◽  
E. M. N. Al-Fawadi ◽  
A. A. Alnajjar
Keyword(s):  
Room Temperature ◽  
Thermal Evaporation ◽  
High Accuracy ◽  
Compositional Dependence ◽  
X Ray Diffraction ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Glass Substrates ◽  
Different Temperatures ◽  
Good Agreement

Results of a study of alloys and films with various Pb content have been reported and discussed. Films of of thickness 1.5 μm have been deposited on glass substrates by flash thermal evaporation method at room temperature, under vacuum at constant deposition rate. These films were annealed under vacuum around 10−6Torr at different temperatures up to 523 K. The composition of the elements in alloys was determined by standard surfaces techniques such as atomic absorption spectroscopy (AAS) and X-ray fluorescence (XRF), and the results were found of high accuracy and in very good agreement with the theoretical values. The structure for alloys and films is determined by using X-ray diffraction. This measurement reveals that the structure is polycrystalline with cubic structure and there are strong peaks at the direction (200) and (111). The effect of heat treatment on the crystalline orientation, relative intensity, and grain size of films is presented.

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