X-ray- and Neutron-diffraction Studies with Quasicrystalline and Amorphous Al-V- and Al-Mn-alloys

1990 ◽  
Vol 45 (5) ◽  
pp. 627-638
Author(s):  
S. Seehafer ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Neutron Diffraction ◽  
Coordination Number ◽  
Correlation Functions ◽  
Melt Spinning ◽  
Pair Correlation ◽  
Partial Density ◽  
Isomorphous Substitution ◽  
Hard Sphere Model ◽  
X Ray ◽  
Structure Factors

Abstract Amorphous and quasicrystalline samples of Al84Mn16 and Al84V16 were produced by sputtering and melt-spinning, respectively. From X-ray and neutron-diffraction-results the total structure factors were evaluated. For amorphous as well as for quasicrystalline Al84V16 the partial SAl-Al- and SAl-V-structure factors were obtained, which yield the corresponding partial pair correlation functions, the atomic distances, and the partial coordination numbers. Also some information concerning the partial Bhatia-Thornton correlation functions could be obtained. Both the amorphous and the quasicrystalline Al-V-alloys show a linear expansion by a factor of 1.03 compared to the corresponding Al-Mn-alloy. The two amorphous alloys can be designed as isomorphous, whereas the quasicrystalline ones show pronounced deviations in the distance between unequal atoms. The shortest atomic distance in amorphous Al84V16 is 2.69 A, being,formed by Al-V-pairs with a coordination number 2. The nearest Al-Al-distance amounts to 2.84 A with a coordination number 8. The partial density-concentration correlation function clearly deviates from the hard sphere model. With the quasicrystalline specimens, the isomorphous substitution of Mn- and V-atoms is not perfect. The Al-V-correlation is split up, and this is not observed for the Al-Mn-correlation. Comparison of the amorphous and the corresponding quasicrystalline alloy shows some similarities

scholarly journals X-Ray and Neutron Diffraction of Amorphous Nickel-Zirconium-Alloys as Prepared in Different Ways

1991 ◽  
Vol 46 (6) ◽  
pp. 491-498 ◽  
Author(s):  
L. Schultz ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Neutron Diffraction ◽  
Short Range ◽  
Melt Spinning ◽  
Short Range Order ◽  
Pair Correlation ◽  
Zirconium Alloys ◽  
X Ray ◽  
Coordination Numbers ◽  
Structure Factors ◽  
The One

AbstractThe structure of amorphous NiχZr100-χ-alloys (Χ= 30, 31, 34, 63.7, and 65), which were produced by melt spinning (MS), mechanical alloying (MA), and sputtering (SP) was studied by X-ray- and neutron diffraction yielding structure factors, pair correlation functions, coordination numbers, atomic distances, and Warren-Cowley chemical short range order parameters. The atomic arrangement within the first coordination sphere is independent of the method of preparation while in the second and higher spheres it differs between the MS- and the MA-alloys on the one side and the SP-specimens on the other side. Thus one understands that some physical properties of the different specimens differ

X-ray Diffraction Study of Amorphous NixZr(100-x)-Alloys Prepared by Melt-Spinning

1991 ◽  
Vol 46 (11) ◽  
pp. 947-950
Author(s):  
W.-M. Kuschke ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Melt Spinning ◽  
Pair Correlation ◽  
Nickel Concentration ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coordination Numbers ◽  
Structure Factors ◽  
Wide Range ◽  
Good Agreement

AbstractAmorphous Ni-Zr-alloys can be prepared by melt-spinning within a wide range of composition. Studies by X-ray diffraction yielded structure factors, pair correlation functions, total coordination numbers and atomic distances in dependence on the nickel concentration in the range of 25 up to 45 atomic percent. The change of the total coordination number and atomic distances turned out to be linear with the composition in this range. This is in good agreement with the linear composition dependence of the superconducting transition temperature, magnetic susceptibility, crystallization temperature, and electrical resistivity in the investigated range of composition.

X-Ray Investigations on Molten Cu-Sb Alloys

1994 ◽  
Vol 49 (4-5) ◽  
pp. 530-534 ◽  
Author(s):  
Th. Halm ◽  
H. Neumann ◽  
W. Hoyer
Keyword(s):  
Electronic Properties ◽  
Structure Factor ◽  
Correlation Functions ◽  
Pair Correlation ◽  
Model Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Factors ◽  
Diffraction Structure ◽  
Eutectic Concentration

Abstract Using X-ray diffraction, structure factors and pair correlation functions of several molten Cu-Sb alloys and pure antimony were determined and compared with published structural, thermodynamic and electronic properties. The eutectic concentration Cu37Sb63 was investigated in dependence on temperature, and a model structure factor was calculated applying a segregation model.

scholarly journals Evaluation of the Structure of Amorphous Tungsten Oxide W28O72 by the Combination of Electron-, X-Ray- and Neutron-Diffraction (Three-Beam Experiment)

2006 ◽  
Vol 61 (3-4) ◽  
pp. 189-196 ◽  
Author(s):  
Jürgen Ankele ◽  
Joachim Mayer ◽  
Peter Lamparter ◽  
Siegfried Steeb
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Data ◽  
Structural Model ◽  
Pair Correlation ◽  
Electron Diffraction Data ◽  
X Ray ◽  
Structure Factors ◽  
Beam Experiment ◽  
Reverse Monte Carlo Simulation ◽  
Sputter Deposited

From the combination of quantitative electron-diffraction data with X-ray- and neutron-diffraction data (so-called three-beam experiment) the partial structure factors and pair correlation functions of amorphous sputter deposited W28O72 were determined. On the basis of the experimental atomic distances and coordination numbers, and by comparison with crystalline WO3, a structural model was developed, which consists of twisted WO6 octahedra. Reverse Monte Carlo simulation in accordance with the experimental data was performed to verify the results

X-Ray Diffraction with Molten AuxMn100-x-Alloys

1995 ◽  
Vol 50 (9) ◽  
pp. 831-836
Author(s):  
R. M. Hagenmayer ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Correlation Functions ◽  
Short Range ◽  
Short Range Order ◽  
Pair Correlation ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Pair Correlation Functions ◽  
X Ray ◽  
Structure Factors ◽  
Total Structure

Abstract The molten alloys Au28.5Mn71.5 and Au68Mn32 are investigated with the energy dispersive X-ray diffraction method which works rather fast so that the evaporation loss of Mn from the molten alloys is kept low. From the observed prepeak follows that both melts are compound-forming but the gold rich melt Au68Mn32 shows only 50% of the short range order existent within the Au28.5Mn71.5 melt. Total structure factors and total pair correlation functions are discussed.

Structure of Molten Sn-Zn-Alloys by Means of Neutron Diffraction

1978 ◽  
Vol 33 (10) ◽  
pp. 1151-1153 ◽  
Author(s):  
Walter Knoll ◽  
Siegfried Steeb
Keyword(s):  
Neutron Diffraction ◽  
Small Angle ◽  
Correlation Functions ◽  
Pair Correlation ◽  
Small Angle Scattering ◽  
Pair Correlation Functions ◽  
Structure Factors ◽  
Angle Scattering ◽  
Total Structure ◽  
Zn Alloys

Abstract Neutron diffraction experiments were performed with four molten Sn-Zn-alloys and the two molten elements Sn and Zn. The total structure factors and the pair correlation functions are given. The observed small angle scattering leads to the result that pairs of equal atoms predominate within the range of medium concentrations.

Structure of Molten Bi-Zn-Alloys by Means of Neutron Diffraction

1983 ◽  
Vol 38 (4) ◽  
pp. 395-398 ◽  
Author(s):  
W. Knoll ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Neutron Diffraction ◽  
Concentration Dependence ◽  
Correlation Functions ◽  
Pair Correlation ◽  
Nearest Neighbour ◽  
Pair Correlation Functions ◽  
Coordination Numbers ◽  
Structure Factors ◽  
Total Structure ◽  
Zn Alloys

Neutron diffraction experiments were performed with five molten Bi-Zn-alloys and the two molten elements Bi and Zn. The total structure factors and the pair correlation functions are given. The concentration dependence of the experimental nearest neighbour distances and the experimental coordination numbers is in accordance with the segregation behaviour prevailing in these melts.

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