Atomic Structure of Amorphous Fe-Tb-and Amorphous Fe-Co-Tb-Alloys by Means of EDXD

1989 ◽  
Vol 44 (12) ◽  
pp. 1201-1209 ◽  
Author(s):  
R. Utz ◽  
A. Brunsch ◽  
P. Lamparter ◽  
S. Steeb

Abstract We present structural investigations using the energy dispersive X-ray diffraction (EDXD)- method on amorphous Fe-Tb- and Fe-Co-Tb-alloys over an extended concentration range. Atomicdistances. partial coordination numbers, and chemical short range order parameters are reported. The short range order is characterized by a compound forming tendency. In an amorphous Fe-Co- Tb-alloy, doping with hydrogen affects the short range order and gives rise to an in-plane magnetization direction.

1990 ◽  
Vol 195 ◽  
Author(s):  
J. Weissmüller ◽  
J. Jing ◽  
A. Krämer ◽  
R. Birringer ◽  
U. Gonser ◽  
...  

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.


1987 ◽  
Vol 42 (1) ◽  
pp. 7-12 ◽  
Author(s):  
A. Müller ◽  
E. Bühler ◽  
P. Lamparter ◽  
S. Steeb

Amorphous Co25Ti75 could be produced using the melt-spin-technique. A neutron- and a X-ray-diffraction experiment was performed. Assuming SNC ≡ 0 the partial Bhatia Thornton structure factors SNN and SCC as well as the partial coordination numbers were calculated. The discussion yields the atomic distances and the chemical short range order parameters.


2022 ◽  
Vol 64 (2) ◽  
pp. 261
Author(s):  
O.V. Sidorova ◽  
L.A. Aleshina ◽  
A.D. Fofanov

The structure of amorphous-crystalline titanite obtained by mechanical activation was studied by X-ray diffraction and simulation methods. The short-range order characteristics were calculated using Finbak-Warren's method. It was found that the coordination numbers of metal atoms decreased as the result of titanite grinding. The atomic configurations of short-range order of ground titanite were constructed by translation of titanite unit cell. The theoretical X-ray patterns were calculated using Debye's method and were compared with the experimental curves. The structure of ground titanite in the mill with centrifugal factor 40 g was described satisfactorily by the model of mechanical mixture of clusters containing 2016 atoms, disordered during the molecular dynamics with clusters containing 12096 atoms. The increase of grinding intensity led to the sharp decrease of sizes of small cluster.


1987 ◽  
Vol 42 (4) ◽  
pp. 421-425
Author(s):  
A. Müller ◽  
E. Bühler ◽  
P. Lamparter ◽  
S. Steeb ◽  
R. Bellissent ◽  
...  

Using the method of isotopic substitution from two neutron- and one X-ray-diffraction experiment the three partial Bhatia Thornton- as well as Faber Ziman-structure factors were determined with amorphous Cu50Ti50. The discussion yields the partial coordination numbers and atomic distances as well as the short range order parameters.


1998 ◽  
Vol 05 (02) ◽  
pp. 459-464 ◽  
Author(s):  
L. D. Marks ◽  
D. Grozea ◽  
R. Feidenhans'l ◽  
M. Nielsen ◽  
R. L. Johnson

The atomic structure of the Au 6 × 6 on Si(111) phase has been determined using direct methods and surface X-ray diffraction data. This surface structure is very complicated, with 14 independent gold atoms, relaxations in 24 independent silicon sites and three partially occupied gold sites. In one sense the structure can be described as microdomains of the parent [Formula: see text] on Si(111) structure. A better description is in terms of a tiling of incomplete pentagonal and trimer units, essentially a pseudopentagonal glass. In terms of these structural units it appears possible to explain all the gold structures in the coverage range of 0.8–1.5 monolayers as pseudoglasses with strong short range order but varying degrees of long range order.


1975 ◽  
Vol 30 (12) ◽  
pp. 1633-1639 ◽  
Author(s):  
W. Hoyer ◽  
E. Thomas ◽  
M. Wobst

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".


1987 ◽  
Vol 22 (12) ◽  
pp. 4357-4361 ◽  
Author(s):  
R. A. Ligero ◽  
J. Vázquez ◽  
P. Villares ◽  
R. Jimńez-Garay

Author(s):  
J. D. Londono ◽  
A. Habenschuss ◽  
J. G. Curro ◽  
J. J. Rajasekaran

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 ◽  
...  

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.


1981 ◽  
Vol 36 (8) ◽  
pp. 880-885 ◽  
Author(s):  
W. Hoyer ◽  
B. Kunsch ◽  
M. Suda ◽  
E. Wieser

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.


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