scholarly journals Структура халькогенидного стеклообразного полупроводника Se-=SUB=-95-=/SUB=-As-=SUB=-5-=/SUB=-, легированного примесью EuF-=SUB=-3-=/SUB=-

2019 ◽  
Vol 53 (11) ◽  
pp. 1540
Author(s):  
С.Н. Гарибова ◽  
А.И. Исаев ◽  
С.И. Мехтиева ◽  
С.У. Атаева
Keyword(s):  
Raman Scattering ◽  
Local Structure ◽  
Amorphous Matrix ◽  
Chemical Activity ◽  
Chemical Bonds ◽  
Structural Elements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glassy Semiconductor ◽  
Chalcogenide Glassy Semiconductor

The local structure of film samples of chalcogenide glassy semiconductor Se95As5 and Se95As5(EuF3)x (x = 0.01 ÷ 1 at%) have been studied by X-ray diffraction and Raman scattering. The ‘‘quasi-period’’ of the structure, the correlation length, the structural elements and chemical bonds that form the amorphous matrix of the materials studied have been determined. Interpretation of results obtained has been carried out within the framework of the Elliot voidscluster model, taking into account the chemical activity of europium ions.

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.

X-ray microprobe for materials science

1994 ◽  
Vol 52 ◽  
pp. 56-57
Author(s):  
G.E. Ice
Keyword(s):  
Crystallographic Orientation ◽  
Local Structure ◽  
Materials Science ◽  
Chemical Information ◽  
X Ray Diffraction ◽  
Ray Optics ◽  
X Ray ◽  
Novel Materials ◽  
New Information ◽  
Elemental Sensitivity

The increasing availability of synchrotron x-ray sources has stimulated the development of advanced hard x-ray (E≥5 keV) microprobes. With new x-ray optics these microprobes can achieve micron and submicron spatial resolutions. The inherent elemental and crystallographic sensitivity of an x-ray microprobe and its inherently nondestructive and penetrating nature will have important applications to materials science. For example, x-ray fluorescent microanalysis of materials can reveal elemental distributions with greater sensitivity than alternative nondestructive probes. In materials, segregation and nonuniform distributions are the rule rather than the exception. Common interfaces to whichsegregation occurs are surfaces, grain and precipitate boundaries, dislocations, and surfaces formed by defects such as vacancy and interstitial configurations. In addition to chemical information, an x-ray diffraction microprobe can reveal the local structure of a material by detecting its phase, crystallographic orientation and strain.Demonstration experiments have already exploited the penetrating nature of an x-ray microprobe and its inherent elemental sensitivity to provide new information about elemental distributions in novel materials.

Local atomic structure in tetragonal pure ZrO2nanopowders

2010 ◽  
Vol 43 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Leandro M. Acuña ◽  
Diego G. Lamas ◽  
Rodolfo O. Fuentes ◽  
Ismael O. Fábregas ◽  
Márcia C. A. Fantini ◽  
...  
Keyword(s):  
Tetragonal Phase ◽  
Local Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Structures ◽  
Crystallite Sizes ◽  
Exafs Study ◽  
The Difference ◽  
X Ray Absorption ◽  
Good Agreement

The local atomic structures around the Zr atom of pure (undoped) ZrO2nanopowders with different average crystallite sizes, ranging from 7 to 40 nm, have been investigated. The nanopowders were synthesized by different wet-chemical routes, but all exhibit the high-temperature tetragonal phase stabilized at room temperature, as established by synchrotron radiation X-ray diffraction. The extended X-ray absorption fine structure (EXAFS) technique was applied to analyze the local structure around the Zr atoms. Several authors have studied this system using the EXAFS technique without obtaining a good agreement between crystallographic and EXAFS data. In this work, it is shown that the local structure of ZrO2nanopowders can be described by a model consisting of two oxygen subshells (4 + 4 atoms) with different Zr—O distances, in agreement with those independently determined by X-ray diffraction. However, the EXAFS study shows that the second oxygen subshell exhibits a Debye–Waller (DW) parameter much higher than that of the first oxygen subshell, a result that cannot be explained by the crystallographic model accepted for the tetragonal phase of zirconia-based materials. However, as proposed by other authors, the difference in the DW parameters between the two oxygen subshells around the Zr atoms can be explained by the existence of oxygen displacements perpendicular to thezdirection; these mainly affect the second oxygen subshell because of the directional character of the EXAFS DW parameter, in contradiction to the crystallographic value. It is also established that this model is similar to another model having three oxygen subshells, with a 4 + 2 + 2 distribution of atoms, with only one DW parameter for all oxygen subshells. Both models are in good agreement with the crystal structure determined by X-ray diffraction experiments.

scholarly journals Exploring the fundamental effects of deposition time on the microstructure of graphene nanoflakes by Raman scattering and X-ray diffraction

CrystEngComm ◽  
2011 ◽  
Vol 13 (1) ◽  
pp. 312-318 ◽  
Author(s):  
Navneet Soin ◽  
Susanta Sinha Roy ◽  
Christopher O'Kane ◽  
James A. D. McLaughlin ◽  
Teck H. Lim ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Deposition Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Nanoflakes

scholarly journals Evidence of a symmetric disordered ice above ~62 GPa from Raman scattering and X-ray diffraction investigations

1996 ◽  
Vol 52 (a1) ◽  
pp. C535-C535
Author(s):  
E. Wolanin ◽  
Ph. Pruzan ◽  
M. Gauthier ◽  
J. C. Chervin ◽  
B. Canny ◽  
...  
Keyword(s):  
Raman Scattering ◽  
X Ray Diffraction ◽  
X Ray

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).

High-pressure effect on inverse spinel LiCuVO4: X-ray diffraction and Raman scattering

2013 ◽  
Vol 22 (1) ◽  
pp. 016103 ◽  
Author(s):  
Heng-Nan Liang ◽  
Chun-Li Ma ◽  
Fei Du ◽  
Qi-Liang Cui ◽  
Guang-Tian Zou
Keyword(s):  
High Pressure ◽  
Raman Scattering ◽  
Pressure Effect ◽  
X Ray Diffraction ◽  
Inverse Spinel ◽  
X Ray ◽  
High Pressure Effect
Sign in / Sign up

Export Citation Format

Share Document