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

Short Range Structure of Amorphous Ni50Ta50-Alloys by Means of X-Ray- and Neutron-Diffraction

1992 ◽  
Vol 47 (7-8) ◽  
pp. 826-832 ◽  
Author(s):  
H. Uhlig ◽  
L. Rohr ◽  
H.-J. Güntherodt ◽  
P. Fischer ◽  
P. Lamparter ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Short Range ◽  
Short Range Order ◽  
Nearest Neighbor ◽  
Range Order ◽  
Partial Structure ◽  
X Ray ◽  
Coordination Numbers ◽  
Binding Behavior ◽  
Structure Factors

Abstract Amorphous Ni50Ta50-samples with their high crystallization temperature of 985 K were investigated. To evaluate the three partial structure factors of amorphous Ni50Ta50 one X-ray diffraction experiment was performed with Ni50Ta50 and two neutron diffraction experiments with Co10Ni40Ta50 and with Ni50Ta50, respectively. The Bhatia-Thornton partial structure factor SCC(Q) indicates rather strong chemical short range order which also explains the premaximum observed in the Faber-Ziman partial SNiNi(Q)-function. The nearest neighbor distance is 2.82 Å for Ni-Ni, 2.91 Å for Ta-Ta, and is shortest for Ni-Ta, 2.44 Å. The coordination numbers are NNiNi = 4.9, NTaTa = 8.2, and NNiTa = 6.0. We report on the chemical short range order and the possible binding behavior in a-Ni50Ta50 and compare the present results with those reported in the literature on a-Ni40Ti60 as well as on a-Ni55Ta45

Structure of Molten Mn74Si26 and Molten Mn33.5Si66.5 by Neutron Diffraction

1997 ◽  
Vol 52 (8-9) ◽  
pp. 645-649
Author(s):  
B. Sedelmeyer ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Correlation Function ◽  
Neutron Diffraction ◽  
Order Parameter ◽  
Short Range ◽  
Short Range Order ◽  
Pair Correlation ◽  
Range Order Parameter ◽  
Compound Formation ◽  
X Ray ◽  
Coordination Numbers

Abstract Molten Mn74Si26 and molten Mn33.5Si66.5 were investigated by neutron diffraction. The pair correlation function yielded, together with the X-ray results from a former paper, the partial coordination numbers, atomic distances, and the short range order parameter with the result that the atomic distribution in molten Mn33.5Si66.5 is statistical while the structure factor of molten Mn74Si26 , as obtained with neutrons, shows a strong prepeak which means rather strong compound formation.

An X-ray and Neutron Scattering Study of the Structure of Zinc Vanadate Glasses

2001 ◽  
Vol 56 (6-7) ◽  
pp. 478-488
Author(s):  
Uwe Hoppe ◽  
Rainer Kranold ◽  
Emil Gattef ◽  
Jörg Neuefeind ◽  
David A. Keen
Keyword(s):  
Neutron Diffraction ◽  
Coordination Number ◽  
Short Range ◽  
Short Range Order ◽  
X Ray ◽  
Coordination Numbers ◽  
Gaussian Functions ◽  
Scattering Study ◽  
Neutron Scattering Study ◽  
Vanadate Glasses

Abstract The short-range order of vitreous V20 5 and of three (Zn0)Jt(V20 5)1_x glasses with x = 0.2, 0.4, and 0.5 is studied by X-ray and neutron diffraction experiments where the change of the contrast allows to resolve the V -0 and Z n -0 correlations. The V -0 and the Z n -0 first-neighbor peaks are approximat­ ed by several Gaussian functions. In case of vitreous V20 5 two obvious V -0 distances exist which are related with V 0 4 and V 0 5 units. With ZnO additions the V -O coordination number decreases from 4.4 in vitreous V20 5 to 4.0 in the metavanadate glass where the strongest decrease of the fraction of V 0 5 units is found for glasses of * < 0.2. Dominantly, the V 0 5 groups are linked with the neighboring units by comers. The Z n-0 coordination numbers of the modified glasses are about five with closest dis­ tances of = 0.200 nm.

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.

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- 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 Structure Factors of Liquid Cu-Pb Alloys by Neutron Diffraction

1980 ◽  
Vol 35 (11) ◽  
pp. 1178-1181 ◽  
Author(s):  
Peter Lamparter ◽  
Siegfried Steeb
Keyword(s):  
Neutron Diffraction ◽  
Order Parameter ◽  
Short Range ◽  
Short Range Order ◽  
Marked Effect ◽  
Pair Correlation ◽  
Nearest Neighbour ◽  
Critical Composition ◽  
Structure Factors ◽  
Angle Scattering

Abstract By means of neutron diffraction the structure factors and pair correlation functions of five Cu-Pb alloys, Cu, and Pb in the liquid state have been determined. The nearest neighbour distances have been obtained. The marked effect of small angle scattering with the melt with critical composition (65 at % Cu) is a proof for microsegregation tendency. By comparison with a segregation model for the structure factor the short range order parameter has been derived for melts with 65 and 35 at % Cu, respectively.

Structural Investigation of the Metallic Glasses Mg85.5Cu14.5 and Mg70Zn30

1983 ◽  
Vol 38 (2) ◽  
pp. 142-148 ◽  
Author(s):  
E. Nassif ◽  
P. Lamparter ◽  
W. Sperl ◽  
S. Steeb
Keyword(s):  
Short Range ◽  
Short Range Order ◽  
Pair Correlation ◽  
Range Order ◽  
Order Effects ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Factors ◽  
Similar Chemical ◽  
Total Structure

Abstract The total structure factors as well as the total pair correlation functions for amorphous Mg85.5Cu14.5 (by neutron and X-ray diffraction) and for amorphous Mg70Zn30 (by X-ray diffraction) were determined. Both alloys show similar chemical short range order effects. From the total pair correlation function of the Mg85.5Cu14.5 glass, partial coordination numbers and atomic distances could be extracted. Comparison with the structure of crystalline Mg2Cu suggests that the short range order around the copper atoms is similar in the amorphous and the crystalline phase. The densities of both amorphous alloys were measured yielding negative excess volumina.

Neutron- and X-ray-Diffraction Study on the Structure of Amorphous Co25Ti75

1987 ◽  
Vol 42 (1) ◽  
pp. 7-12 ◽  
Author(s):  
A. Müller ◽  
E. Bühler ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Diffraction Study ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Diffraction Experiment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coordination Numbers ◽  
Structure Factors ◽  
Melt Spin

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.

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.

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