Fe K-Edge XAFS Study of Slate Powders Heat Treated up to 1000°C

2010 ◽  
Vol 636-637 ◽  
pp. 922-927
Author(s):  
Fernando A. Costa Oliveira ◽  
Hiroaki Nitani ◽  
T. Nakagawa ◽  
T.A. Yamamoto ◽  
Nobumitsu Shohoji
Keyword(s):  
Synchrotron Radiation ◽  
Short Range ◽  
Short Range Order ◽  
Colour Change ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Increasing Temperature ◽  
Radiation Beams ◽  
Variable Energy

The use of ultra-bright, highly directional, high and variable energy associated to synchrotron radiation beams at SPring-8 when compared with conventional X-Ray diffraction analysis applied to slate powders heat treated at temperatures in the range of 600°C up to 1000°C is reported. Fe K-edge XAFS measurements of the products formed upon heating slate showed that in the temperature range 600-800°C, conversion of FeO present in the as-received slate powder into a mixed -Fe2O3/-Fe2O3 has occurred providing useful information on the short-range order atomic structure of the slate. Above 800°C, mainly -Fe2O3 was identified to be present in the slate. The change of the Fe valences within the slate network is most likely responsible for the detected colour change with the increasing temperature.

Röntgenbeugungsuntersuchung an geschmolzenem Selen und Tellur sowie an Legierungen des Systems Selen—Tellur/ X-ray Diffraction Study of Molten Selenium, and Tellurium and of Molten Selenium — Tellurium-Alloys

1975 ◽  
Vol 30 (12) ◽  
pp. 1633-1639 ◽  
Author(s):  
W. Hoyer ◽  
E. Thomas ◽  
M. Wobst
Keyword(s):  
Chain Length ◽  
Short Range ◽  
Short Range Order ◽  
Coordination Shell ◽  
Range Order ◽  
Average Chain Length ◽  
X Ray Diffraction ◽  
Coordination Numbers ◽  
Nearest Neighbours ◽  
Increasing Temperature

Abstract At temperatures just above the melting point molten Selenium seems to be a mixture of long chains and eight-membered rings. With increasing temperature the number of rings and the average chain length decrease. At 460 °C the average chain length lies in the range of 10 atoms.In a slightly supercooled Tellurium-melt the number of first neighbours is two. The atoms are arranged in chains. Selenium rich Se-Te-alloy-melts are built up of mixed chains. It seems to be possible, that a smaller part of atoms forms Se6Te2 rings. At Tellurium concentrations higher than approximately 50 at.-% the chainlike structure with two next nearest neighbours changes to a disturbed Arsen-like short range order. The number of electrons in the first coordination shell, the short range order parameter introduced by Cowley and the partial coordination numbers show that Se-Te-alloys are of the "solution system" type, but in the whole concentration range for each atom there is a tendency to have "strange coordination".

Short-range order in some alloys of the Ge-As-Te semiconducting glassy system by X-ray diffraction

1987 ◽  
Vol 22 (12) ◽  
pp. 4357-4361 ◽  
Author(s):  
R. A. Ligero ◽  
J. Vázquez ◽  
P. Villares ◽  
R. Jimńez-Garay
Keyword(s):  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
X Ray Diffraction ◽  
Glassy System ◽  
X Ray

Short-range order in some polymer melts from X-ray diffraction

1996 ◽  
Vol 34 (17) ◽  
pp. 3055-3061 ◽  
Author(s):  
J. D. Londono ◽  
A. Habenschuss ◽  
J. G. Curro ◽  
J. J. Rajasekaran
Keyword(s):  
Short Range ◽  
Short Range Order ◽  
Polymer Melts ◽  
Range Order ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals X-ray diffraction study of structure of CaO-Al2O3-SiO2 ternary compounds in molten and crystalline states

2020 ◽  
Vol 56 (2) ◽  
pp. 269-277
Author(s):  
V.E. Sokol’skii ◽  
D.V. Pruttskov ◽  
O.M. Yakovenko ◽  
V.P. Kazimirov ◽  
O.S. Roik ◽  
...  
Keyword(s):  
Short Range ◽  
Room Temperature ◽  
Short Range Order ◽  
Structural Parameters ◽  
Range Order ◽  
Reverse Monte Carlo ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Ternary Compounds

Anorthite and gehlenite crystalline structure and short-range order of anorthite melt have been studied by X-ray diffraction in the temperature range from room temperature up to ~ 1923 K. The corresponding anorthite and gehlenite phases were identified as well as amorphous component for anorthite samples having identical shape to XRD pattern of the anorthite melt. The structure factor and the radial distribution function of atoms of the anorthite melt were calculated from the X-ray high-temperature experimental data. The partial structural parameters of the short-range order of the melt were reconstructed using Reverse Monte Carlo simulations.

Structure Investigations on Se1-xTex Melts by Neutron Scattering and X-ray Diffraction

1981 ◽  
Vol 36 (8) ◽  
pp. 880-885 ◽  
Author(s):  
W. Hoyer ◽  
B. Kunsch ◽  
M. Suda ◽  
E. Wieser
Keyword(s):  
Correlation Function ◽  
Neutron Scattering ◽  
Diffraction Data ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nearest Neighbours ◽  
Structure Investigations

Abstract Neutron scattering results on Se1-xTex melts (x = 0.3, 0.6, 0.8) obtained at 460 °C are combined with earlier X-ray diffraction data. The behaviour of the number and distance of nearest neighbours is discussed with respect to chemical short-range order and transition from twofold to three-fold coordination. For Se70Te30 the radial concentration correlation function 4πr2 ρcc(r) has been evaluated. It shows clearly the preferred formation of unlike pairs (Se-Te) within the chains.

X-Ray Diffraction Study of Atomic Short-Range Order in Pt–15.0 at.% Cr Alloy

2002 ◽  
Vol 71 (10) ◽  
pp. 2456-2458 ◽  
Author(s):  
Dilip Kumar Saha ◽  
Toetsu Shishido ◽  
Ken-ichi Ohshima
Keyword(s):  
Diffraction Study ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
X Ray Diffraction ◽  
X Ray

Noncrystalline Solids Prepared by Compacting Nanometer — Sized Particles

1990 ◽  
Vol 195 ◽  
Author(s):  
J. Weissmüller ◽  
J. Jing ◽  
A. Krämer ◽  
R. Birringer ◽  
U. Gonser ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Atomic Structure ◽  
Short Range ◽  
Short Range Order ◽  
Amorphous Solids ◽  
Range Order ◽  
New Method ◽  
X Ray Diffraction ◽  
X Ray

ABSTRACTA new method of preparing amorphous solids is presented. X-ray diffraction, thermal stability and Mgssbauer spectroscopy give evidence for an atomic structure with reduced short–range order in Si75Auz5 and Pd72FeloSil8 alloys prepared by this method.

Undercooling And X-Ray Structural Studies Of Ti-Zr-Ni Liquids

2002 ◽  
Vol 754 ◽  
Author(s):  
G.W. Lee ◽  
A.K. Gangopadhyay ◽  
K.F. Kelton ◽  
R.W. Hyers ◽  
T.J. Rathz ◽  
...  
Keyword(s):  
Short Range ◽  
Short Range Order ◽  
Icosahedral Phase ◽  
Range Order ◽  
X Ray Diffraction ◽  
Containerless Processing ◽  
X Ray ◽  
Ni Alloys ◽  
Nucleation Barrier ◽  
Maximum Undercooling

ABSTRACTMaximum undercooling results for the icosahedral phase (i-phase), polytetrahedral C14 Laves phase, and solid solution phases are presented as a function of composition in Ti-Zr-Ni liquids. Containerless processing was achieved using the electrostatic levitation facility located at NASA/Marshall Space Flight Center. The maximum reduced undercooling decreases with increasing icosahedral short-range order in the ordered phase. The first synchrotron x-ray diffraction data from aerodynamically levitated liquids of Ti-Zr-Ni alloys suggest an icosahedral short-range order in the liquids, supporting Frank's hypothesis, correlating icosahedral order in the liquid with the nucleation barrier to the crystal phase. The strong negative heats of mixing between Ti/Zr and Ni and their relative atomic sizes likely favor the formation of this local icosahedral order.

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