scholarly journals Contributions of Electron Microscopy to the Understanding of Reactions on Compound Semiconductor Surfaces

1985 ◽  
Vol 62 ◽  
Author(s):  
T. Sands
Keyword(s):  
Electron Microscopy ◽  
Rutherford Backscattering Spectrometry ◽  
Compound Semiconductor ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Glancing Angle ◽  
Semiconductor Substrates ◽  
The Relationship ◽  
Minimum Quality

ABSTRACTReacted films on compound semiconductor substrates present challenging materials characterization problems which often require the application of transmission electron microscopy (TEM) techniques. In this paper, both the problem - solving potential of the TEM techniques and the limits imposed by preparation of thin film/compound semiconductor TEM specimens are discussed. Studies of the Ni/GaAs, CuCl(aq)/CdS and Pd/GaAs reactions exemplify the role of TEM in identifying and determining the spatial distribution of interface - stabilized polymorphs and new ternary phases (e.g. tetragonal Cu2S, Ni3GaAs and PdxGaAs). These examples also serve to clarify the relationship between TEM and complementary analysis techniques such as Rutherford backscattering spectrometry, Auger electron spectroscopy and glancing-angle x-ray diffraction. In particular, it is argued that a combination of (1) high-spatial-resolution information obtained by TEM and (2) an indication of the “average” behavior provided by data from a complementary characterization technique provide the minimum quality and quantity of data necessary to understand most reactions on compound semiconductor substrates.

Microstructural evolution of dense and porous pyroelectric Pb1−xCaxTiO3 thin films

1999 ◽  
Vol 14 (5) ◽  
pp. 2012-2022 ◽  
Author(s):  
Andreas Seifert ◽  
Laurent Sagalowicz ◽  
Paul Muralt ◽  
Nava Setter
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Microstructural Evolution ◽  
Rutherford Backscattering Spectrometry ◽  
X Ray Diffraction ◽  
Porous Films ◽  
Transmission Electron ◽  
Ca Substitution ◽  
High Figure ◽  
Low Permittivity

Pb1−xCaxTiO3 thin films with x = 0−0.3 for pyroelectric applications were deposited on platinized silicon wafers by chemical solution processing. Ca-substitution for Pb in PbTiO3 results in a reduced c/a ratio of the unit cell, which, in turn, leads to better pyroelectric properties. Control of nucleation and growth during rapid thermal annealing to 650 °C allowed the formation of either highly porous or dense (111) oriented films. The inclusion of pores creates a matrix-void composite with the low permittivity desired for pyroelectric applications, resulting in a high figure of merit. The growth mechanisms for the microstructural evolution of both dense and porous films were analyzed by x-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Rutherford backscattering spectrometry and allowed establishment of microstructure/property relationships.

PLD Grown 3C-SiC Thin Films on Si: Morphology and Structure

2015 ◽  
Vol 821-823 ◽  
pp. 213-216
Author(s):  
S.M. Ryndya ◽  
N.I. Kargin ◽  
A.S. Gusev ◽  
E.P. Pavlova
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Rutherford Backscattering Spectrometry ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Selected Area Electron Diffraction ◽  
Atomic Force ◽  
Transmission Electron ◽  
Influence Of Substrate ◽  
Composition Structure

Silicon carbide thin films were obtained on Si (100) and (111) substrates by means of vacuum laser ablation of α-SiC ceramic target. The influence of substrate temperature on composition, structure and surface morphology of experimental samples was examined using Rutherford backscattering spectrometry (RBS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), conventional and high-resolution transmission electron microscopy (TEM/HRTEM), atomic force microscopy (AFM), selected area electron diffraction (SAED) and X-ray diffraction (XRD) methods.

scholarly journals Synthesis of ZnO Nanostructures by Microwave Irradiation Using Albumen as a Template

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
T. Prakash ◽  
R. Jayaprakash ◽  
G. Neri ◽  
Sanjay Kumar
Keyword(s):  
Electron Microscopy ◽  
Microwave Irradiation ◽  
Fast Method ◽  
Zno Nanostructures ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Ft Ir ◽  
Size And Morphology ◽  
Microwave Assisted Method

ZnO nanostructures have been successfully prepared by a microwave irradiation method. The role of albumen as a template in addressing the size and morphology of ZnO has been investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG-DTA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. A heterogeneous mixture of Zn(OH)2 and ZnO was obtained in absence of albumen. Pure ZnO nanostructures, consisting of rod- and whisker-like nanoparticles embedded in a sheet matrix, were obtained in the presence of albumen. Optical and photoluminescence (PL) properties of the synthesized samples were also compared. Results obtained indicate that the microwave-assisted method is a promising low temperature, cheap, and fast method for the production of ZnO nanostructures.

Crystalline and microstructure study of the AlN–Al2O3section in the Al–N–O system. II. φ′- and δ-AlON spinel phases

1999 ◽  
Vol 32 (2) ◽  
pp. 253-272 ◽  
Author(s):  
P. Tabary ◽  
C. Servant
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Model ◽  
Spinel Phase ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Spinel Phases ◽  
Two Phases ◽  
Microscopy Techniques ◽  
The Relationship

Results from the crystalline and microstructure study of the φ′- and δ-AlON spinel phases by X-ray diffraction, neutron diffraction and standard-resolution transmission electron microscopy techniques are reported. Several samples having different compositions in mol % AlN were considered. A structural model is proposed to account for the double modulation of composition and displacement of the cations and anions, which has been determined for these two phases and for the relationship with the γ-AlON spinel phase. Some high-resolution transmission electron microscopy experiments have confirmed the present structural model. A discussion with reference to previous data is presented.

Effects of Thermo-Mechanical Treatment on the Microstructure of AA7085 Aluminum Alloy

2014 ◽  
Vol 794-796 ◽  
pp. 1193-1198 ◽  
Author(s):  
Hong Wei Tong ◽  
Wen Yi Liu ◽  
Guang Jie Huang ◽  
Qing Liu
Keyword(s):  
Electron Microscopy ◽  
Rolled Plate ◽  
X Ray Diffraction ◽  
Warm Deformation ◽  
X Ray ◽  
Free Zone ◽  
Transmission Electron ◽  
Hardness Tests ◽  
Continuous Chain

The microstructure of pre-aged AA7085 rolled plate was studied by means of hardness tests, optical microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and electrical conductivity tests. The results show that supper refined and homogeneous precipitates were formed during pre-aging, but the hardness of the alloy was still relatively low. There occurred a large number of dislocations when the warm deformation was introduced, and the size of the intragranular precipitates firstly increases and then decreases and then increases with the dislocation density increasing, which was caused by the role of dislocations on inhibiting the formation of GP zone and promoting the nucleation and transformation ofηphase. Meanwhile, the distribution of grain boundary precipitates also changed from continuous chain to coarsening interrupted distribution and the precipitate free zone (PFZ) broadened obviously.

Short Term Oxidation of a Ti-46Al-8Nb Alloy at 700°C in Air

2010 ◽  
Vol 636-637 ◽  
pp. 485-490 ◽  
Author(s):  
Paul Erve T. Ngnekou ◽  
Marie Christine Lafont ◽  
François Senocq ◽  
Jacques Lacaze ◽  
Bernard Viguier
Keyword(s):  
Electron Microscopy ◽  
Total Duration ◽  
Outer Part ◽  
Parabolic Rate Constant ◽  
Oxidation Behaviour ◽  
X Ray Diffraction ◽  
Short Term ◽  
X Ray ◽  
Transmission Electron ◽  
Glancing Angle

Thermogravimetry was used to study the oxidation behaviour of a lamellar Ti46Al8Nb alloy during holding at 700°C in synthetic air. A parabolic plot of the oxidation kinetics shows three different regimes over the total duration (50 h) of the tests corresponding to decreasing values of the parabolic rate constant. The oxide scale was characterized by glancing-angle X-Ray diffraction and transmission electron microscopy. The scale was found to be bi-layered with an outer part that consists of amorphous aluminium rich oxide whilst the inner layer is made of very small cristalites of titania distributed in the same amorphous oxide.

Epitaxial Growth of 3C-SiC by Pulsed Laser Deposition

1995 ◽  
Vol 410 ◽  
Author(s):  
J. E. Cosgrove ◽  
P. A. Rosenthal ◽  
D. Hamblen ◽  
D. B. Fenner ◽  
C. Yang
Keyword(s):  
Electron Microscopy ◽  
Pulsed Laser Deposition ◽  
Rutherford Backscattering Spectrometry ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Auger Microprobe ◽  
Substrate Types

ABSTRACTWe have grown thin films of SiC by pulsed laser deposition on silicon (100) and vicinal and non-vicinal 6H SiC (0001) substrates using a quadrupled YAG laser and a high purity dense polycrystalline SiC target. Epitaxy on all three substrate types was confirmed by x-ray diffraction, transmission electron microscopy and electron diffraction. Composition of the films was measured by Rutherford backscattering spectrometry and Scanning Auger Microprobe.

scholarly journals Effects of Pr and Yb Dual Doping on the Thermoelectric Properties of CaMnO3

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1807 ◽  
Author(s):  
Cuiqin Li ◽  
Qianlin Chen ◽  
Yunan Yan
Keyword(s):  
Electron Microscopy ◽  
Figure Of Merit ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Thermoelectric Figure ◽  
X Ray ◽  
Transmission Electron ◽  
New Strategy ◽  
Low Toxicity

There has been research on CaMnO3 with natural abundance, low toxicity, and low cost as promising candidates for n-type thermoelectric (TE) materials. In this paper, Ca1−2xPrxYbxMnO3 with different Pr and Yb contents (x = 0, 0.01, 0.02, 0.03, 0.04 and 0.05) were synthesized by means of coprecipitation. With X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM), researchers characterized the phase structure and morphology of all the samples. The oxidation states of manganese were determined by X-ray photoemission spectroscopy (XPS). The role of Ca-site dual doping in the TE properties was also investigated. Increasing the Pr and Yb contents leads to decreases in the electrical resistivity and Seebeck coefficient, leading to a power factor of 3.48 × 10−4 W·m−1·K−2 for x = 0.04 at 773 K, which is its maximum. Furthermore, the thermal conductivity (κ) decreases with increasing x, and κ = 1.26 W m−1·K−1 is obtained for x = 0.04 at 973 K. Ca0.92Pr0.04Yb0.04MnO3 exhibit a ZT (thermoelectric figure of merit) value of 0.24 at 973 K, approximately 3 times more than that of the pristine CaMnO3. Thus, the reported method is a new strategy to enhance the TE performance of CaMnO3.

scholarly journals Synthesis and Characterization of Molybdenum Disulfide Nanoflowers and Nanosheets: Nanotribology

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
S. V. Prabhakar Vattikuti ◽  
Chan Byon
Keyword(s):  
Electron Microscopy ◽  
Tribological Performance ◽  
Wear Scar ◽  
Engine Oil ◽  
Sulfur Source ◽  
X Ray Diffraction ◽  
Interface Surface ◽  
Transmission Electron ◽  
The Relationship

This paper reports the solvothermal synthesis of MoS2nanoflowers and nanosheets. The nanoflowers have a mean diameter of about 100 nm and were obtained using thioacetamide (C2H5NS) as a sulfur source. The few layered nanosheets were obtained using thiourea (CH4N2S) as a sulfur source. The obtained powders were characterized using powder X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The lubricating effect of MoS2nanoflowers and nanosheets were analyzed using four-ball test, the topography of the wear scar was analyzed using SEM, EDS, and 3D surface profilometry. The relationship between the tribological properties and morphology of the materials was determined. It is observed that the engine oil containing the MoS2nanomaterials penetrated more easily into the interface space, and it formed a continuous film on the interface surface. The tribological performance showed that the synthesized nanosheets had superior antiwear and friction-reducing properties as a lubrication additive compared with nanoflowers. Also, the wear scar of balls lubricated with nanoflowers revealed a larger diameter compared to nanosheets. In conclusion, nanosheets dispensed in oil have better tribological performance compared to nanoflowers oil in terms of capability to reduce friction.

scholarly journals Growth and Characterization of Ni Nano-Micro Structures in the Presence of Ethylenediamine

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 397 ◽  
Author(s):  
Lingxiao Chen ◽  
Hang Liu ◽  
Linghao Liu ◽  
Yifan Zheng ◽  
Haodong Tang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Alkaline Conditions ◽  
Naoh Solution ◽  
Micro Structures ◽  
Scanning Electron

Ni nano-micro structures have been synthesized via a solution reduction route in the presence of ethylenediamine (EDA) under strong alkaline conditions. The phase composition, morphology, and microstructure of the resulting products are investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The presence of EDA plays an important role in the formation of Ni nano-micro structures, and microflowers or microspheres assembled from nanosized horns can be produced by changing the amount of EDA. The size of Ni nano-micro structures is dependent on the NaOH concentration, and long chains assembled from Ni nano-micro structured microspheres can be obtained by reducing the amount of NaOH solution used. The role of both EDA and NaOH in the reduction of Ni (II) to Ni, as well as in the growth of Ni nano-micro structures, has been discussed, and a possible formation mechanism of these Ni nano-micro structures has been proposed based on the experimental results.

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