Atomic Structure of Amorphous Metallic Ni81B19

1982 ◽  
Vol 37 (11) ◽  
pp. 1223-1234 ◽  
Author(s):  
P. Lamparter ◽  
W. Sperl ◽  
S. Steeb
Keyword(s):  
Neutron Diffraction ◽  
Pair Correlation ◽  
Isotopic Substitution ◽  
Diffraction Experiment ◽  
Substitution Method ◽  
Distance Correlation ◽  
Coordination Numbers ◽  
Chemical Ordering ◽  
Structure Factors ◽  
Soft Spheres

The three partial Faber Ziman structure factors as well as the Bhatia Thornton structure factors of the metallic glass Ni81B19 were evaluated by neutron diffraction experiments using the isotopic substitution method. In one of the investigated specimens the isotopic composition of the components was adjusted in such a way as to make it possible to measure directly with one diffraction experiment the correlation between the metalloid atoms. From the three partial pair correlation functions the atomic distances and the partial coordination numbers are determined. The results demonstrate the strong chemical ordering in amorphous Ni81B19. Particularly the distance correlation between the boron atoms turned out to be very pronounced.The experimental results agree with the main features of a geometrical packing model of soft spheres.

Neutron Diffraction Study on the Structure of the Metallic Glass Cu57Zr43

1983 ◽  
Vol 38 (11) ◽  
pp. 1210-1222 ◽  
Author(s):  
P. Lamparter ◽  
S. Steeb ◽  
E. Grallath
Keyword(s):  
Neutron Diffraction ◽  
Metallic Glasses ◽  
Neutron Diffraction Study ◽  
Isotopic Substitution ◽  
Substitution Method ◽  
Chemical Ordering ◽  
Structure Factors ◽  
Theoretical Investigations ◽  
Binary Metallic Glasses ◽  
Scattering Contribution

The structure of amorphous Cu57Zr43 has been investigated by neutron diffraction using the isotopic substitution method with the isotopes 63Cu and 65Cu besides natural Cu. From the scattering contribution of concentration fluctuations to the measured structure factors and from the atomic distances chemical ordering is concluded to exist in amorphous Cu57Zr43. The structural results are compared with previous experimental and theoretical investigations of Cu- Zr- and other binary metallic glasses formed by transition metals. Evidence is given that the topological as well as the chemical short range order is asymmetric in respect to both components in this type of metallic glasses

Local Structure of the Amorphous Ni25Zr75-Alloy by Using the Isotope-Substitution Neutron Diffraction Method

1991 ◽  
Vol 46 (11) ◽  
pp. 951-954
Author(s):  
W.-M. Kuschke ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Neutron Diffraction ◽  
Local Structure ◽  
Short Range ◽  
Short Range Order ◽  
Diffraction Method ◽  
Isotopic Substitution ◽  
Isotope Substitution ◽  
Coordination Numbers ◽  
Structure Factors ◽  
Neutron Diffraction Method

AbstractUsing neutron diffraction as well as the method of isotopic substitution the partial Bhatia-Thornton as well as the partial Faber-Ziman structure factors of amorphous Ni25Zr75 were determined. A compound forming tendency was found. The atomic distances, partial coordination numbers, and the chemical short range order parameter are evaluated.

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

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.

Structure of the Molten 37 a/o Cu-63 a/o Sb Alloy Using the Isotopic Substitution Method in Neutron Diffraction

1978 ◽  
Vol 33 (4) ◽  
pp. 472-479 ◽  
Author(s):  
W. Knoll ◽  
S. Steeb
Keyword(s):  
Neutron Diffraction ◽  
Pair Correlation ◽  
Neutron Diffraction Study ◽  
Number Density ◽  
Partial Structure ◽  
Distance Correlation ◽  
Structure Factors ◽  
Total Structure ◽  
The Fourier Transform ◽  
Strong Segregation

A neutron diffraction study of the eutectic Cu-Sb-melt containing 37 a/o Cu has been performed using isotopically enriched samples. The three partial structure factors describing the Cu-Cu, Cu-Sb, and Sb-Sb correlations have been determined as well as a second set of partial structure factors relating to the distance correlation of fluctuations in number density and concentration. Unsmoothed total structure factors were used. By Fourier-transformation the corresponding pair correlation functions were obtained. A strong segregation tendency was found. Concentration fluctuations with a correlation length of 2.4 Å could be determined. From the Fourier-transform of SCC the product N̄1α1 was obtained confirming the segregation tendency. The distance of nearest Cu-Cu neighbours in the eutectic Cu-Sb melt was found to be smaller than in pure molten Cu, whereas the Sb-Sb distance is larger than in pure Sb. According to Faber-Ziman theory the electrical resistivity was calculated and compared with experimental data.

Neutron Diffraction with the Metallic Glass Ni31Dy69 ( + 10 a/o D) Using Isotopic Substitution

1985 ◽  
Vol 40 (2) ◽  
pp. 191-192
Author(s):  
A. Wildermuth ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Amorphous Alloy ◽  
Neutron Diffraction ◽  
Metallic Glass ◽  
Structure Factor ◽  
Isotopic Substitution ◽  
Diffraction Experiment ◽  
Partial Structure ◽  
Neutron Diffraction Experiment ◽  
Partial Structure Factor ◽  
Structure Factors

By neutron diffraction using the method of isotopic substitution with the amorphous alloy Ni31Dy69 the partial structure factors SNiNi, SDyDy and SNiDy were obtained, furthermore with the same specimen containing 10 a/o deuterium a partial structure factor SDD resulted. For the evaluation of SDD it was necessary to perform the neutron diffraction experiment with an alloy whose both components were zero scattering isotopic mixtures of Ni or Dy, respectively.

Neutron- and X-Ray-Diffraction Study on the Structure of Amorphous Cu50Ti50

1987 ◽  
Vol 42 (4) ◽  
pp. 421-425
Author(s):  
A. Müller ◽  
E. Bühler ◽  
P. Lamparter ◽  
S. Steeb ◽  
R. Bellissent ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Isotopic Substitution ◽  
Diffraction Experiment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coordination Numbers ◽  
Structure Factors

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.

Variations of the Partial Short Range Order Structure of Amorphous Ni32Pd52P16 During Relaxation Using Neutron Diffraction and Isotopic Substitution

1988 ◽  
Vol 43 (12) ◽  
pp. 1055-1060 ◽  
Author(s):  
M. Schaal ◽  
Ρ. Lamparter ◽  
S. Steeb
Keyword(s):  
Neutron Diffraction ◽  
Coordination Sphere ◽  
Scattering Length ◽  
Pair Correlation ◽  
Order Structure ◽  
Isotopic Substitution ◽  
Heat Treated ◽  
Structure Factors ◽  
Main Effect ◽  
Relaxation Procedure

Melt spun amorphous Ni32Pd52P16 specimens were produced using natNi, the isotope 60Ni, and an isotopic mixture ∅Ni with zero-scattering length. The specimens were heat treated for two hours at 496, 533, 570, and 607 K, respectively, and investigated by neutron diffraction. The Faber-Ziman structure factors as well as the total pair correlation functions show rather large effects caused by the relaxation procedure. By convenient combination of the total functions conclusions on the behaviour of the Ni-Ni, Ni-Pd, Ni-P, Pd-Ni, Pd-Pd, Pd-P, P-Ni, and P-Pd partial coordina­tion numbers and atomic distances during the relaxation procedure are obtained. Relaxation has no detectable influence on the nearest neighbourhood but leads to variations in the region of the second Ni-Ni coordination sphere (3.7 Å ≦ R ≦ 5.7 Å) with the main effect that after heat treatment at 607 K, 2 h, the second Ni-Ni coordination sphere is subdivided into three distinct subspheres. It is suggested that the relaxation process mainly involves the redistribution of bond angles.

Electron Diffraction with the Amorphous Alloys Fe80B20 and Mn73Si27

1982 ◽  
Vol 37 (11) ◽  
pp. 1215-1222
Author(s):  
F. Paasche ◽  
H. Olbrich ◽  
G. Rainer-Harbach ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Electron Diffraction ◽  
Neutron Diffraction ◽  
Amorphous Alloys ◽  
Pair Correlation ◽  
Diffraction Experiment ◽  
Partial Structure ◽  
Neutron Diffraction Experiment ◽  
X Ray ◽  
Structure Factors ◽  
Beam Experiment

Electron diffraction with amorphous Fe80B20 and Mn73Si27 yields structure factors and pair correlation functions which are discussed together with the results of X-ray- and neutron-diffraction experiments. For Mn73Si27 additional interesting details are revealed. A tetrahedral model for Mn73Si27 is described. Finally we show that the evaluation of partial structure factors by the three beam experiment, i.e. the combination of an electron-, X-ray- and neutron-diffraction experiment is not possible in general.

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