X-Ray Diffraction and Reflectance, Raman Scattering and Photoluminescence Characterization of Thermally Annealed Epitaxial SI1-XGEX Layers

1993 ◽  
Vol 298 ◽  
Author(s):  
M. LíbeznÝ ◽  
I. De Wolf ◽  
J. Poortmans ◽  
A. Van Ammel ◽  
M. Caymax ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Strained Layers ◽  
Reflectance Measurement ◽  
Thermally Induced ◽  
Capping Layer ◽  
X Ray ◽  
Pl Spectra

AbstractSil-xGex, undoped strained layers with a pure Si-capping layer were grown epitaxially by UHV CVD on Si (100) substrates. The samples were subjected to thermal treatments corresponding to typical deviceprocessing. Effects connected with thermally induced relaxations were studied by Raman scattering, XRD, photoluminescence (PL) and defect etching. The thickness of the layers was determined from X-ray reflectance measurement. Strain values for the as-grown and relaxed samples were extracted from Raman scattering, XRD measurements and defect etching and correlated. Sil-xGex-layer related peaks were observed in PL spectra of several samples. An explanation why those peaks are not observed in all the samples is suggested.

scholarly journals Preparation and characterization of magnetite-based silica nanocomposite

2004 ◽  
pp. 121-129 ◽  
Author(s):  
Mihaela Popovici ◽  
Cecilia Savii ◽  
Daniel Niznanský ◽  
Jan Subrt ◽  
Eva Vecernikova ◽  
...  
Keyword(s):  
Thermal Analyses ◽  
Sol Gel ◽  
Nitrogen Atmosphere ◽  
Thermal Treatments ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Magnetite Phase

Sol-gel method and successive thermal treatments in vacuum and nitrogen atmosphere were employed to synthesize magnetite nanoparticles isolate them with the aid of amorphous silica. Thermogravimetric and differential thermal analyses coupled with mass spectrometry, X-ray diffraction, transmission electron microscopy, M?ssbauer spectroscopy and vibrating sample magnetometry measurements were performed on the obtained nanocomposites. The effect of atmosphere on the formation of magnetite phase was remarkable.

Crystallographic characterization of fluorapatite glass-ceramics synthesized from industrial waste

2017 ◽  
Vol 32 (S2) ◽  
pp. S61-S65 ◽  
Author(s):  
Chee W. Loy ◽  
Khamirul A. Matori ◽  
Norhazlin Zainuddin ◽  
Andrew E. Whitten ◽  
Christine Rehm ◽  
...  
Keyword(s):  
Rice Husk Ash ◽  
Glass Ceramics ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Thermally Induced ◽  
X Ray ◽  
Glass Forming ◽  
Amorphous Silicate ◽  
Silicate Matrices

A series of phase transformations of a novel fluoroaluminosilicate glass forming a range of fluorapatite glass-ceramics on sintering are reported. The sintering process induces formation of fluorapatite, mullite, and anorthite phases within the amorphous silicate matrices of the glass-ceramics. The fluoroaluminosilicate glass, SiO2–Al2O3–P2O5–CaO–CaF2, is prepared from waste materials, such as rice husk ash, pacific oyster shells, and disposable aluminium cans. The thermally induced crystallographic and microstructure evolution of the fluoroaluminosilicate glass towards the fluorapatite glass-ceramics, with applications in dental and bone restoration, are investigated by powder X-ray diffraction and small-angle neutron-scattering techniques.

RAMAN SCATTERING AND X-RAY DIFFRACTION CHARACTERIZATION OF AMORPHOUS SEMICONDUCTOR MULTILAYER INTERFACES

1985 ◽  
Vol 56 ◽  
Author(s):  
J. GONZALEZ ◽  
D.D. ALLRED ◽  
O.V. NGUYEN ◽  
D. MARTIN ◽  
D. PAWLIK
Keyword(s):  
Raman Spectroscopy ◽  
Raman Scattering ◽  
Raman Spectra ◽  
Amorphous Semiconductor ◽  
Chemical Bonds ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sharp Interfaces ◽  
Deposition Techniques

AbstractIn the present study, Raman spectroscopy (RS) and x-ray diffraction have been used to characterize semiconductor multilayer interfaces. A model for Raman spectra of multilayers is developed and applied to the specific case of the interfaces of a-Si/a-Ge multilayers. Quantification of the ‘blurring’ of interfaces is possible because RS is capable of directly ‘counting’ the total number of chemical bonds of a given type in the film. Multilayers, prepared by various deposition techniques, are compared. Several a-Si/a-Ge multilayers deposited by UHV evaporation (MBD) exhibit exceptionally sharp interfaces (intermixing width <l.0Å) and regular periodicities.

scholarly journals Physical and catalytic characterization of smectites from Boa-Vista, Paraíba, Brazil

Cerâmica ◽  
2003 ◽  
Vol 49 (311) ◽  
pp. 146-150 ◽  
Author(s):  
M. G. F. Rodrigues
Keyword(s):  
Acid Treatment ◽  
Nitrogen Adsorption ◽  
Model Reaction ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Natural Form ◽  
X Ray ◽  
Smectite Clays ◽  
Catalytic Characterization

The original crystalline structure of clay minerals can be altered in a controlled way, through acid or thermal treatments, resulting then in suitable products to be used as catalysts. This paper aims to characterize the red smectite clays of Boa-Vista, Paraíba (Brazil) in their natural form, and after chemical, thermal and acid treatments by X-ray fluorescence, differential thermal analysis, dynamic X-ray diffraction, classic X-ray diffraction analysis, scanning electron microscopy, nitrogen adsorption and model reaction. The results show that acid treatment partially altered the structure of the montimorillonite. An important increase in the surface area of the solid obtained was observed. The obtained reaction for the treated material showed that the clay was more acid than the natural one, yielding a better catalytic activity.

Characterization of sputtered films of Tl2Ba2CaCu2O8 using Raman scattering and x-ray diffraction

1991 ◽  
Vol 182 (4-6) ◽  
pp. 231-240 ◽  
Author(s):  
J. Chrzanowski ◽  
J.C. Irwin ◽  
B. Heinrich ◽  
A.E. Curzon ◽  
N. Fortier ◽  
...  
Keyword(s):  
Raman Scattering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputtered Films

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.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

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