Structural Studies Of Epitaxial CdF2 Layers on Si(111)

1996 ◽  
Vol 441 ◽  
Author(s):  
A. Yu. Khilko ◽  
R. N. Kyutt ◽  
G. N. Mosina ◽  
N. S. Sokolov ◽  
Yu. V. Shusterman ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Optimal Growth ◽  
Misfit Strain ◽  
X Ray Diffraction ◽  
Optimal Growth Temperature ◽  
Light Emitting ◽  
X Ray ◽  
Light Emitting Devices ◽  
Transmission Electron

AbstractEpitaxial CdF2 layers, which may be used in light-emitting devices integrated with silicon, were grown by Molecular Beam Epitaxy (MBE). Characterization of the layers by Rutherford Backscattering Spectroscopy (RBS), X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) showed that optimal growth temperature lies in the range 60–80°C. The sticking coefficient of CdF2 molecules was found to decrease at temperatures above 100°C. Different modes of misfit strain relaxation were observed above and below that temperature.

Optical Characterization of Zinc Selenide Compound Prepared through Hydrothermal Method

2016 ◽  
Vol 846 ◽  
pp. 237-244
Author(s):  
Fakhrurrazi Ashari ◽  
Josephine Liew Ying Chyi ◽  
Zainal Abdib Talib ◽  
W. Wahmood Wan Yunus ◽  
Leong Yong Jian ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Hydrothermal Reaction ◽  
Electronic Devices ◽  
Band Gap Energy ◽  
Photovoltaic Devices ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
Light Emitting Devices

ZnSe which show a potential application in electronic devices such as photovoltaic devices, light emitting devices and photodetector have been synthesized through a hydrothermal method using ZnCl2 and Se powder as the source. In a typical synthesis, Zn2+ and Se2- ion have been prepared separately and charged into a Teflon-lined stainless steel autoclave. The hydrothermal reaction was conducted at 180 °C for 32 hours. Structural properties of ZnSe are studied by X-ray diffraction (XRD) while the optical properties of ZnSe compound are characterized through ultraviolet–visible spectroscopy (UV-Vis). From the XRD result, pure ZnSe with main XRD peak at 2θ = 27.29°, 45.30°, 53.62°, 65.88°, 72.68° has been observed. The result have been supported by the optical results where absoprtion peak at 460 nm with optical band gap energy (Eg) at 2.5 eV.

Structure Characterization of Epitaxial Strain Relaxation in YBa2Cu3O7−x/PrBa2Cu3O7 Superlattices

2000 ◽  
Vol 619 ◽  
Author(s):  
María Varela ◽  
Diego Arias ◽  
Zouhair Sefrioui ◽  
Carlos León ◽  
Carmen Ballesteros ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Strain Relaxation ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Epitaxial Strain ◽  
Transmission Electron ◽  
High Oxygen Pressure ◽  
Unit Cells

ABSTRACTThe structure of c-axis oriented [YBa2Cu3O7−(YBCO) N / PrBa2Cu3O7 (PBCO)M/1000Å superlattices with N ranging between 1 and 12 and M=5 unit cells, grown by high oxygen pressure sputtering on (100) SrTiO3 substrates, is analyzed by x-ray diffraction (XRD) and highresolution transmission electron microscopy (HREM). The XRD spectra refinement shows epitaxial strain for YBCO thickness below 4 unit cells. For larger YBCO layer thickness, stress relaxes and step disorder builds up. HREM observations show sharp and flat interfaces between substrate and superlattice stack. The only observable defects are isolated steps or a-axis oriented domains in relaxed samples. The results of both structural tools are compared.

STRUCTURAL AND OPTICAL CHARACTERIZATION OF ITO/PS HETEROJUNCTION

2008 ◽  
Vol 15 (03) ◽  
pp. 301-306
Author(s):  
B. NATARAJAN ◽  
N. JEYAKUMARAN ◽  
S. RAMAMURTHY ◽  
V. VASU
Keyword(s):  
Indium Tin Oxide ◽  
Spray Pyrolysis Technique ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
Light Emitting Devices ◽  
Transparent Conducting ◽  
P Type ◽  
Luminescent Behavior

Transparent conducting indium tin oxide (ITO) films are deposited on Porous Silicon (PS) substrates by spray pyrolysis technique. In this process, the films are formed over the surface and also incorporated into the pores of PS and thereby making a protecting layer as well as a contacting terminal. Thus, the ITO/PS/ Si heterojunction light-emitting devices are fabricated. The growth of ITO on PS is thoroughly investigated by SEM and X-ray diffraction techniques. The features of growth on other substrates like single-crystal p-type (100) silicon and glass are also taken into consideration. The influence on the PS interface is correlated with the electrical and luminescent behavior of the resulting heterojunction diode structure.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Detonation Synthesis of Nano-Size Materials

1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nucleation And Growth ◽  
Detonation Synthesis ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Nano Size

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.

One Step Synthesis and Characterization of Zirconia-Graphene Composites

2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

Hydrothermal Synthesis and Characterization of BiFeO3 Polyhedral Crystallites

2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.

scholarly journals Characterization of ferrite nanoparticles for preparation of biocomposites

2017 ◽  
Vol 8 ◽  
pp. 1257-1265 ◽  
Author(s):  
Urszula Klekotka ◽  
Magdalena Rogowska ◽  
Dariusz Satuła ◽  
Beata Kalska-Szostko
Keyword(s):  
Chemical Method ◽  
Ferrite Nanoparticles ◽  
Chemical Activity ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
X Ray ◽  
Transmission Electron ◽  
Wet Chemical

Ferrite nanoparticles with nominal composition Me0.5Fe2.5O4 (Me = Co, Fe, Ni or Mn) have been successfully prepared by the wet chemical method. The obtained particles have a mean diameter of 11–16 ± 2 nm and were modified to improve their magnetic properties and chemical activity. The surface of the pristine nanoparticles was functionalized afterwards with –COOH and –NH2 groups to obtain a bioactive layer. To achieve our goal, two different modification approaches were realized. In the first one, glutaraldehyde was attached to the nanoparticles as a linker. In the second one, direct bonding of such nanoparticles with a bioparticle was studied. In subsequent steps, the nanoparticles were immobilized with enzymes such as albumin, glucose oxidase, lipase and trypsin as a test bioparticles. The characterization of the nanoparticles was acheived by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray and Mössbauer spectroscopy. The effect of the obtained biocomposites was monitored by Fourier transform infrared spectroscopy. The obtained results show that in some cases the use of glutaraldehyde was crucial (albumin).

Solvothermal synthesis and characterization of well-dispersed cerium-doped Y2SiO5 phosphor particles

2021 ◽  
Vol 112 (10) ◽  
pp. 812-816
Author(s):  
Xianxue Li
Keyword(s):  
Solvothermal Method ◽  
Luminescence Decay ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fluorescence Spectrophotometry ◽  
Decay Properties ◽  
Transmission Electron ◽  
Water As Solvent ◽  
Pure Phase

Abstract Well-dispersed cerium-doped Y2SiO5 (Ce:YSO) phosphor particles with spherical morphology and good luminescence intensity have been achieved by a solvothermal method with ethanol and water as solvent media. X-ray diffraction, Fourier transform infrared spectroscopy, fluorescence spectrophotometry and transmission electron microscopy were employed to characterize the as-synthesized Ce:YSO precursor and powders. The results showed that pure-phase Ce:YSO powders with a mean particle size of about 162 nm were accurately available at 310°C and above. The fluorescence ability and persistent luminescence decay properties of the Ce:YSO powders were also studied, and the excellent fluorescence properties could be attributed to the homogeneous Ce:YSO particles obtained through the solvothermal method.

Preparation and Characterization of Pt/Superfine Mesocarbon Microbead Powers Electrocatalysts

2005 ◽  
Vol 3 (3) ◽  
pp. 358-360 ◽  
Author(s):  
Jia Rong-Li ◽  
Wang Cheng-Yang ◽  
Zhu Bin
Keyword(s):  
Reduction Method ◽  
Direct Methanol Fuel Cells ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Platinum Particles ◽  
Platinum Electrocatalyst ◽  
Direct Methanol

Superfine mesocarbon microbead powders (SFMCMBs) as the new supports for platinum electrocatalysts were first investigated. The Pt∕SFMCMB electrocatalysts were prepared by an impregnation-reduction method, with hexachloroplatinic acid as the platinum precursor and formaldehyde as the reducing agent. The catalysts were characterized with x-ray diffraction (XRD), field emission gun transmission electron microscope (TEM), and electrochemical analysis. TEM photos showed the platinum particles were dispersed uniformly on the surface of SFMCMBs and there existed a little aggregation of platinum particles in the Pt∕SFMCMB catalysts. The TEM photos showed the existence of the platinum on the supports where the average platinum particle size were 4-6nm. The electrochemical analysis proved that SFMCMBs are excellent candidates to be used as the support of platinum electrocatalyst for methanol electrochemical oxidation as the potential catalyst candidate for direct methanol fuel cells (DMFCs).

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