scholarly journals Resonant soft x-ray fluorescence studies of novel materials

10.2172/81067 ◽  
1995 ◽  
Author(s):  
J.A. Carlisle ◽  
L.J. Terminello ◽  
E.A. Hudson ◽  
E.L. Shirley ◽  
J.J. Jia ◽  
...  
Keyword(s):  
X Ray ◽  
Fluorescence Studies ◽  
Novel Materials

scholarly journals Resonant Soft X-Ray Fluorescence Studies of Novel Materials

1994 ◽  
Vol 375 ◽  
Author(s):  
J. A. Carlisle ◽  
E. L. Shirley ◽  
L. J. Terminello ◽  
E. A. Hudson ◽  
J. J. Jia ◽  
...  
Keyword(s):  
Pyrolytic Graphite ◽  
Emission Spectra ◽  
Excited Electron ◽  
Core Electron ◽  
Emission Process ◽  
X Ray ◽  
Fluorescence Studies ◽  
Novel Materials ◽  
The Core ◽  
Resonant Emission

AbstractWe are using resonant soft x-ray fluorescence at the Advanced Light Source to probe the electronic and geometric structure of novel materials. In the resonant process, a core electron is excited by a photon whose energy is near the core binding energy. In this energy regime the absorption and emission processes are coupled, and this coupling manifests itself in several ways. In boron nitride (BN), the resonant emission spectra reflect the influence of a “spectator” electron in an unoccupied excitonic state. The resonant emission can be used to distinguish between the various bulk phases of BN, and can also be used to probe the electronic structure of a monolayer of BN buried in a bulk environment, where it is inaccessible to electron spectroscopies. For highly-oriented pyrolytic graphite (HOPG) a coherent absorption-emission process takes place in the resonant regime, whereby crystalline momentum is conserved between the core excited electron and the valence hole which remains after emission

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.

Electronic structure ofBi2Sr2CaCu2O8+δandTl2Ba2CaCu2O8: Near-O-1s-threshold excitation x-ray fluorescence studies

1995 ◽  
Vol 51 (17) ◽  
pp. 11915-11923 ◽  
Author(s):  
S. M. Butorin ◽  
J.-H. Guo ◽  
N. Wassdahl ◽  
P. Skytt ◽  
J. Nordgren ◽  
...  
Keyword(s):  
Electronic Structure ◽  
X Ray ◽  
Fluorescence Studies ◽  
Threshold Excitation

X-Ray and Fluorescence Studies on Phospholipid Bilayers. IX. Interactions with Pentachlorophenol

1990 ◽  
Vol 45 (3-4) ◽  
pp. 265-272 ◽  
Author(s):  
M. Suwalsky ◽  
M. A. Espinoza ◽  
M. Bagnara ◽  
C. P. Sotomayor
Keyword(s):  
Cell Membrane ◽  
Phospholipid Bilayers ◽  
Erythrocyte Membranes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fluorescence Studies ◽  
Human Erythrocyte Membranes ◽  
Cell Membrane Level ◽  
Membrane Level ◽  
Sodium Form

Abstract Pentachlorophenol (PCP) is a widely used and highly toxic fungicide. Its toxicity is mainly expressed at the cell membrane level. It is, therefore, of interest to test its ability to alter the lipid bilayer organization. The present study was performed by X-ray diffraction techniques on dimyristoylphosphatidylethanolamine (DMPE) and dimyristoylphosphatidylcholine (DMPC) bilayers and by fluorescence on DMPC liposomes. These two phospholipids are respectively found at the inner and outer monolayers of human erythrocyte membranes. Each type of phospholipid was made to interact with different concentrations of the sodium form of PCP in absence and in presence of water. It was found that PCP significatively affected the structure of both phospholipids, being the damage much higher in DM PC bilayers.

Pottery production on Rishiri Island, Japan: perspectives from X-ray fluorescence studies

Archaeometry ◽  
2002 ◽  
Vol 44 (2) ◽  
pp. 213-228 ◽  
Author(s):  
M. Hall ◽  
U. Maeda ◽  
M. Hudson
Keyword(s):  
Pottery Production ◽  
X Ray ◽  
Fluorescence Studies

X-Ray Grazing Angle Scattering and Fluorescence Studies of Interfacial Microstructures in Si1-xGex/Si Multilayers

1992 ◽  
Vol 280 ◽  
Author(s):  
Z. H. Ming ◽  
A. Krol ◽  
Y. L. Soo ◽  
Y. H. Kao ◽  
J. S. Park ◽  
...  
Keyword(s):  
Angular Dependence ◽  
Grazing Angle ◽  
Grazing Incidence ◽  
Fluorescence Yield ◽  
Interfacial Roughness ◽  
Density Profiles ◽  
X Ray ◽  
Fluorescence Studies ◽  
X Ray Scattering ◽  
Angle Scattering

ABSTRACTAngular dependence of grazing incidence x-ray scattering and Ge fluorescence yield were measured for the heterostructures of Si1-xGex/Si and the inverted bilayer Si/Si1-xGex as well as two 10-period superlattices. Interfacial roughness, correlation of height fluctuations between interfaces and Ge density profiles in the multilayers were investigated.

scholarly journals Towards triptycene functionalization and triptycene-linked porphyrin arrays

2020 ◽  
Vol 16 ◽  
pp. 763-777
Author(s):  
Gemma M Locke ◽  
Keith J Flanagan ◽  
Mathias O Senge
Keyword(s):  
Electron Transfer ◽  
Single Crystal ◽  
Cross Coupling ◽  
X Ray ◽  
Fluorescence Studies ◽  
Coupling Conditions ◽  
Porphyrin Dimer

Herein, 9,10-diethynyltriptycene is investigated for its use as a rigid isolating unit in the synthesis of multichromophoric arrays. Sonogashira cross-coupling conditions are utilized to attach various porphyrins and boron dipyrromethenes (BODIPYs) to the triptycene scaffold. While there are previous examples of triptycene porphyrin complexes, this work reports the first example of a linearly connected porphyrin dimer, linked through the bridgehead carbons of triptycene. Symmetric and unsymmetric examples of these complexes are demonstrated and single crystal X-ray analysis of an unsymmetrically substituted porphyrin dimer highlights the evident linearity in these systems. Moreover, initial UV–vis and fluorescence studies show the promise of triptycene as a linker for electron transfer studies, showcasing its isolating nature.

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