Structural Characterization of Porous Silicon Fabricated by Electrochemical and Chemical Dissolution of Si Wafers

1991 ◽  
Vol 256 ◽  
Author(s):  
S. Miyazaki ◽  
T. Yasaka ◽  
K. Okamoto ◽  
K. Shiba ◽  
K. Sakamoto ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Electron Beam Irradiation ◽  
Complete Recovery ◽  
Porous Si ◽  
Beam Irradiation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Disordered Structure ◽  
Visible Luminescence

ABSTRACTThe structure of porous silicon exhibiting efficient visible photoluminescence has been characterized by using Fourier transformed infrared absorption, Raman scattering and x-ray diffraction. It is shown that the lattice spacing in the porous Si layer expands by about 0.3% in the direction perpendicular to the surface and also a partially disordered structure is existing. Electron beam irradiation causes desorption of hydrogen and fluorine bonds which terminate the surface, resulting in the quenching of the visible luminescence. The chemical etching of such layer has led to complete recovery of the luminescence intensity as well as the hydrogen and fluorine bonds termination.

X-Ray Diffraction and Reflectivity Studies of Thin Porous Silicon Layers

1996 ◽  
Vol 452 ◽  
Author(s):  
D. Buttard ◽  
G. Dolino ◽  
D. Bellet ◽  
T. Baumbach
Keyword(s):  
Porous Silicon ◽  
Structural Information ◽  
Surface Film ◽  
Silicon Layer ◽  
Lattice Parameter ◽  
Porous Silicon Layer ◽  
Interface Thickness ◽  
X Ray Diffraction ◽  
X Ray

AbstractHigh resolution X-ray diffraction and reflectivity have been used for the structural characterization of thin porous silicon layers of p and p+ doping type. Thin porous silicon layers studied either by diffraction or reflectivity, in the range of 10–1000 nm, exhibit several thickness fringes, corresponding to a lateral homogeneity of the layer thickness. The comparison between the experimental results with simulations enables one to deduce structural information relative to the porosity, thickness, lattice parameter as well as interface thickness. For p+ type samples a double fringe system was observed, showing the existence of a surface film probably at the porous silicon layer top surface.

Modification of Dual Phase Filler by Electron Beam Irradiation: Physical Characterization

2002 ◽  
Vol 75 (4) ◽  
pp. 605-616 ◽  
Author(s):  
A. M. Shanmugharaj ◽  
Anil K. Bhowmick
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Carbon Black ◽  
Electron Beam Irradiation ◽  
Surface Oxidation ◽  
Dual Phase ◽  
Beam Irradiation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Abstract Electron beam modification of carbon black (N220) and carbon-silica dual phase filler affects the microstructure of carbon black. This is confirmed from X-ray diffraction studies. The scanning electron microscopy /energy dispersive X-ray analysis reveals surface oxidation, which is further corroborated from nitrogen and iodine adsorptions. Transmission electron microscopy studies show the aggregation of fillers upon electron beam irradiation. Linear fractal dimension calculated by image analysis increases upon irradiation, due to the formation of filler aggregates.

Characterization of Erbium Doped SiO2 Layers Formed On Silicon By Spark Processing

1997 ◽  
Vol 486 ◽  
Author(s):  
John V. St. John ◽  
Jeffery L. Coffer ◽  
Young Gyu Rho ◽  
Patrick Diehl ◽  
Russell F. Pinizzotto ◽  
...  
Keyword(s):  
Rare Earth ◽  
Porous Silicon ◽  
Porous Si ◽  
Rare Earth Ion ◽  
Temperature Oxidation ◽  
X Ray ◽  
Near Ir ◽  
Erbium Doped ◽  
Er Doped

AbstractDeposition of a rare earth salt layer on a silicon substrate with subsequent spark processing yields a porous Si layer and SiO 2 cap doped with the rare earth ion. We have characterized luminescent Er-doped porous SiO2 on Si by scanning electron microscopy, energy dispersive Xray spectroscopy, as well as visible and near IR photoluminescence (PL) spectroscopies. Energydispersive x-ray maps indicate that the erbium concentration in the porous layer can be controlled by varying the molarity of the erbium solution deposited on the substrate prior to spark processing. Visible PL measurements reveal that the concentration of Er3+ is proportional to the resultant intensity of the visible fluorescence transitions; however, for the near IR fluorescence peak at 1.54 gim, self-quenching due to erbium clustering occurs at higher concentrations. Erbium-doped porous silicon layers can also be obtained by diffusion of an erbium salt into porous silicon formed by anodic etching of Si in hydrofluoric acid. Densification of the porous Si layers through high temperature oxidation after erbium diffusion forms erbium-doped SiO2 layers.

Effect of Electron Beam Irradiation Crosslinking on PVA Films

2014 ◽  
Vol 852 ◽  
pp. 304-308
Author(s):  
Guo Liang Dai ◽  
Hong Xiao ◽  
Shi Feng Zhu ◽  
Mei Wu Shi
Keyword(s):  
Electron Beam ◽  
Irradiation Dose ◽  
Electron Beam Irradiation ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Beam Irradiation ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
X Ray

Electron beam irradiation cross-linking of polyvinyl alcohol (PVA) films with the presence of N, N'- methylene bisacrylamide (MBA) were studied, improving the thermal stability. The films unirradiated and irradiated were characterized by ATR-FTIR spectroscopy, X-ray diffraction, differential scanning calorimetry and thermo gravimetric analysis. The PVA films with the presence of MBA would crosslink after irradiation. The crystallinity increased firstly and then decreased as a function of irradiation dose, while the melting temperature decreased with increasing the dose. Beside, the T30%, T50%, T90% and Tmax temperature of degradation increased as the irradiation dose increased.

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.

Synthesis and characterization of TiN / Ti / AISI 410 coatings

2018 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
S Chirino ◽  
Jaime Diaz ◽  
N Monteblanco ◽  
E Valderrama
Keyword(s):  
Synthesis And Characterization ◽  
Photoemission Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Columnar Grains ◽  
Tin Thin Films ◽  
Steel Aisi ◽  
Interacting Surfaces ◽  
Stainless Steel Aisi

The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified.  Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

Sign in / Sign up

Export Citation Format

Share Document