X-ray diffraction and reflectivity characterization of SiGe superlattice structures

1992 ◽  
Vol 7 (5) ◽  
pp. 627-631 ◽  
Author(s):  
A R Powell ◽  
D K Bowen ◽  
M Wormington ◽  
R A Kubiak ◽  
E H C Parker ◽  
...  
1986 ◽  
Vol 82 ◽  
Author(s):  
D.K. Bowen ◽  
M.J. Hill ◽  
B.K. Tanner

ABSTRACTThe application of double crystal X-ray diffractometry and computer simulation to the characterization of lattice parameter variations through the thickness of heteroepitaxial layers is reviewed. The sensitivity is demonstrated in studies of graded layers grown by vapour phase epitaxy. Capping layers significantly affect rocking curves from superlattice structures. The use of glancing angle diffraction to characterize thin, low period multilayers is examined.


1991 ◽  
Vol 220 ◽  
Author(s):  
P. M. Adams ◽  
R. C. Bowman ◽  
V. Arbet-Engols ◽  
K. L. Wang ◽  
C. C. Ahn

ABSTRACTP-I-N diodes whose intrinsic region consists of strained layer superlattices (SLS), separated by 40 nm Si spacers, have been grown by MBE on Si substrates with <100>, <110>, and <111> orientations. These structures have been characterized by x-ray diffraction (XRD) and cross-sectional transmission electron microscopy (XTEM). The dual periodicities in these structures produced unique XRD effects and the quality was highly dependent on substrate orientation. The <100> sample was in general free of defects, whereas the <110> and <111> specimens contained significant numbers of twins and dislocations.


1999 ◽  
Vol 13 (19) ◽  
pp. 663-669
Author(s):  
MING XU ◽  
WENXUE YU ◽  
GUANGMING LUO ◽  
CHUNLING CHAI ◽  
TONG ZHAO ◽  
...  

To solve the problem on the microstructural characterization of metallic superlattices, taking the NiFe/Cu superlattices as example, we show that the structures of metallic superlattices can be characterized exactly by combining low-angle X-ray diffraction with high-angle X-ray diffraction. First, we determine exactly the total film thickness by a straightforward and precise method based on a modified Bragg law from the subsidiary maxima around the low-angle X-ray diffraction peak. Then, by combining with the simulation of high-angle X-ray diffraction, we obtain the structural parameters such as the superlattice period, the sublayer and buffer thickness. This characterization procedure is also applicable to other types of metallic superlattices.


Author(s):  
R. E. Herfert

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.


Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys

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.


2018 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
S Chirino ◽  
Jaime Diaz ◽  
N Monteblanco ◽  
E Valderrama

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.


Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  

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.


2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihaela Flondor ◽  
Ioan Rosca ◽  
Doina Sibiescu ◽  
Mihaela-Aurelia Vizitiu ◽  
Daniel-Mircea Sutiman ◽  
...  

In this paper the synthesis and the study of some complex compounds of Fe(III) with ligands derived from: 2-(4-chloro-phenylsulfanyl)-1-(2-hydroxy-3,5-diiodo-phenyl)-ethanone (HL1), 1-(3,5-dibromo-2-hydroxy-phenyl)-2-phenylsulfanyl-ethanone(HL2), and 2-(4-chloro-phenylsulfanyl)-1-(3,5-dibromo-2-hydroxy-phenyl)-ethanone (HL3) is presented. The characterization of these complexes is based on method as: the elemental chemical analysis, IR and ESR spectroscopy, M�ssbauer, the thermogravimetric analysis and X-ray diffraction. Study of the IR and chemical analysis has evidenced that the precipitates form are a complexes and the combination ratio of M:L is 1:2. The central atoms of Fe(III) presented paramagnetic properties and a octaedric hybridization. Starting from this precipitation reactions, a method for the gravimetric determination of Fe(III) with this organic ligands has been possible. Based on the experimental data on literature indications, the structural formulae of the complex compounds are assigned.


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