Surface Chemistry of Fe Oxide Impregnated Porous Vycor Glass

1991 ◽  
Vol 244 ◽  
Author(s):  
D. Sunil ◽  
H. Rafailovich ◽  
C. Sokolov ◽  
H. D. Gafney ◽  
S. A. Schwarz ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Fine Structure ◽  
Surface Chemistry ◽  
The Other ◽  
Fe Oxide ◽  
Vycor Glass ◽  
X Ray ◽  
Bond Lengths ◽  
Porous Vycor Glass ◽  
X Ray Absorption

ABSTRACTX-ray absorption and Mossbauer spectroscopy were used to study chemical and magnetic properties of photodeposited Fe in Porous Vycor Glass(PVG). Extended X-ray Absorption Fine Structure(EXAFS) measurements of Fe samples show that after photolyzation, the Fe atoms are surrounded by two shells of six oxygen atoms and eight Fe atoms. The Fe-O and Fe-Fe distances are 1.84 °A and 1.99 °A respectively. After heating to 650 °C and 1200 °C shortening of bond lengths are observed. The second shell of Fe in unheated and heated to 650 °C samples have Fe-Fe distances of 3.0 °A and 2.98 °A respectively. Samples consolidated at 1200 °C show the Fe atoms to be surrounded by two shells of Fe atoms at 2.86 and 3.03 °A. This data together with Mossbauer and XANES spectra suggest that Fe exists in two different configrations, one is an Fe-Fe compound and the other is an octahedral Fe oxide similar to Fe2O3.

Mapping Surface Chemistry and Molecular Orientation with Combinatorial Near-Edge X-Ray Absorption Fine Structure Spectroscopy

2004 ◽  
Vol 25 (1) ◽  
pp. 141-149 ◽  
Author(s):  
Daniel A. Fischer ◽  
Kirill Efimenko ◽  
Rajendra R. Bhat ◽  
Sharadha Sambasivan ◽  
Jan Genzer
Keyword(s):  
Fine Structure ◽  
Surface Chemistry ◽  
Molecular Orientation ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

scholarly journals Magnetic Properties and X-ray Absorption Fine-Structure Spectra of CoMn2O4 Nanoparticles

2012 ◽  
Vol 10 (0) ◽  
pp. 643-646 ◽  
Author(s):  
Toshiki Miyasaka ◽  
Akinobu Kurokawa ◽  
Hiromasa Takeuchi ◽  
Shinya Yano ◽  
Takuya Yanoh ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Fine Structure ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

An Extended X-Ray-Absorption Fine-Structure Study of Bond Lengths in GaAs1-xPx

1986 ◽  
Vol 25 (Part 1, No. 2) ◽  
pp. 231-233 ◽  
Author(s):  
Toru Sasaki ◽  
Tomohiro Onda ◽  
Ryoichi Ito ◽  
Nagaatsu Ogasawara
Keyword(s):  
Fine Structure ◽  
Structure Study ◽  
X Ray ◽  
Bond Lengths ◽  
Absorption Fine ◽  
X Ray Absorption

scholarly journals Extended X-ray absorption fine structure of bimetallic nanoparticles

2011 ◽  
Vol 2 ◽  
pp. 237-251 ◽  
Author(s):  
Carolin Antoniak
Keyword(s):  
Magnetic Properties ◽  
Fine Structure ◽  
Wavelet Transforms ◽  
Density Functional ◽  
Bimetallic Nanoparticles ◽  
Crystallographic Structure ◽  
Fept Nanoparticles ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

Electronic and magnetic properties strongly depend on the structure of the material, especially on the crystal symmetry and chemical environment. In nanoparticles, the break of symmetry at the surface may yield different physical properties with respect to the corresponding bulk material. A useful tool to investigate the electronic structure, magnetic behaviour and local crystallographic structure is X-ray absorption spectroscopy. In this review, recent developments in the field of extended X-ray absorption fine structure measurements and in the analysis methods for structural investigations of bimetallic nanoparticles are highlighted. The standard analysis based on Fourier transforms is compared to the relatively new field of wavelet transforms that have the potential to outperform traditional analysis, especially in bimetallic alloys. As an example, the lattice expansion and inhomogeneous alloying found in FePt nanoparticles is presented, and this is discussed below in terms of the influence of employed density functional theory calculations on the magnetic properties.

X-Ray Absorption Study of Ti and Cr Reactions with Triazine and Polyimide

1993 ◽  
Vol 323 ◽  
Author(s):  
K. Konstadinidis ◽  
R. L. Opila ◽  
M. A. Marcus ◽  
K. Short ◽  
A. E. White ◽  
...  
Keyword(s):  
Fine Structure ◽  
Polymer Matrix ◽  
Model Compound ◽  
The Other ◽  
Absorption Study ◽  
X Ray ◽  
Buried Interfaces ◽  
Metal Atoms ◽  
Π Complex ◽  
X Ray Absorption

AbstractIn this paper we present results on the use of x-ray absorption spectroscopy and in particular extended x-ray absorption fine structure (EXAFS) to study non-destructively buried interfaces between polymers and metals. In particular we study the interaction between isolated metal atoms (Ti or Cr) and the surrounding polymer matrix (polyimide or triazine). The metal atoms have been introduced into the polymer matrix using ion-implantation. We find that Cr forms a π complex with the aromatic structures of polyimide and triazine in agreement with model compound and XPS data. Ti on the other hand seems to form Ti-O-C bonds with both polymers.

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