scholarly journals Structure analysis for Fe-based and Ni-based metal-metalloid amorphous alloys

2014 ◽  
Vol 70 (a1) ◽  
pp. C861-C861
Author(s):  
Hiroshi Arima ◽  
Toru Kawamata ◽  
Yoshihiko Yokoyama ◽  
Kazumasa Sugiyama ◽  
Toshiya Otomo
Keyword(s):  
Structure Analysis ◽  
Melt Spinning ◽  
Structural Model ◽  
Nearest Neighbor ◽  
Level Structure ◽  
Pair Correlation ◽  
Amorphous Ribbon ◽  
Chemical Species ◽  
X Ray ◽  
Glassy Alloys

Transition metal-metalloid amorphous systems such as Fe-B and Ni-B are usually applied for the soft magnetic metallic glassy alloys and are counted as one of prominent categories in the field of amorphous alloy technology. Since glass forming ability of these systems correlates closely with the atomic level structure depending on chemical species of metal and metalloid, the local structure analysis for these glassy alloys is strongly required. In order to obtain the reliable structural model for these metal (Fe, Ni)-metalloid (B) amorphous samples, we determined the partial structural functions by combinational use of neutron diffraction (ND) and anomalous X-ray scattering (AXS). The amorphous ribbon samples were produced by the single-roller melt-spinning technique. The AXS measurements at Fe and Ni absorption edges were carried out at BL-7C of Photon Factory, KEK. The ND experiment was performed by using the time-of-flight technique and high intensity total diffractometer, NOVA at MLF, J-PARC. The figure shows the g(r)s for Fe80B20, Ni81B19, and Ni60B40calculated by the interference functions obtained by ND measurements. The dashed lines in the figure indicate the interatomic distances estimated from Goldschmidt atomic radii (Fe: 1.28 Å, Ni: 1.25 Å, B: 0.97 Å). At the nearest neighbor region up to about 3 Å, the first peak could be accounted for a harmony of metal (M)–B and B–B pair correlations and the second peak is mainly contributed by the M-M pair correlation. As for the three dimensional structural modeling of the amorphous samples, reverse Monte Carlo simulation has been performed starting from an initial model of 2,000 atoms with the b.c.c. structure. The present simulation results are found to reproduce the experimental interference functions obtained by the ND, ordinary X-ray diffraction, and AXS measurements. We will present the obtained structural model and local structural units around B including their arrangement.

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- 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 Assessment of chemical species of lead accumulated in tidemarks of human articular cartilage by X-ray absorption near-edge structure analysis

2011 ◽  
Vol 18 (2) ◽  
pp. 238-244 ◽  
Author(s):  
Florian Meirer ◽  
Bernhard Pemmer ◽  
Giancarlo Pepponi ◽  
Norbert Zoeger ◽  
Peter Wobrauschek ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Structure Analysis ◽  
Chemical Species ◽  
Human Articular Cartilage ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

Nanocrystallization of Cobalt Based Metallic Glass

2009 ◽  
Vol 67 ◽  
pp. 25-32 ◽  
Author(s):  
A.P. Srivastava ◽  
Dinesh Srivastava ◽  
K.G. Suresh ◽  
G.K. Dey
Keyword(s):  
Metallic Glass ◽  
Melt Spinning ◽  
Amorphous Ribbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Copper Addition ◽  
Isothermal Analysis ◽  
Effect Of Copper ◽  
Melt Spinning Technique

Effect of copper addition in a Metallic glass 2714A on the nanocrystallization characteristics have been examined in this study. Amorphous ribbon of the alloy composition Co64.5 Fe3.5 Si16.5 B13.5 Ni1Cu1 were prepared by melt spinning technique. Nanocrystallization kinetics was studied using differential scanning calorimeter technique. The kinetic parameters such as activation energy and Avrami exponent were determined using two different non-isothermal analysis methods. The kinetic behavior of individual crystallization event has been rationalized on the basis of these results. The role of addition of copper on the crystallization behavior has been understood by comparing with Metallic glass 2714A. The isothermally annealed nanocrystallized microstructures were characterized by X-ray diffraction.

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

Structure of Mn-Si-Melts by Means of X-Ray Diffraction

1983 ◽  
Vol 38 (10) ◽  
pp. 1093-1097 ◽  
Author(s):  
E. Nassif ◽  
P. Lamparter ◽  
B. Sedelmeyer ◽  
S. Steeb
Keyword(s):  
Structure Factor ◽  
Melt Spinning ◽  
Pair Correlation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coordination Numbers ◽  
Glass Forming ◽  
Structure Factors ◽  
Total Structure Factor ◽  
Total Structure

Abstract The binary molten alloys Mn74Si26 and Mn33.5Si66.5 have been investigated by means of X-ray diffraction. The total structure factors as well as the total pair correlation functions were evaluated. The interatomic distances and total coordination numbers are given. The structural results for Mn74Si26 were compared to those for amorphous Mn74Si23P3 and for a tetrahedral packing model. A pronounced shoulder on the second maximum of the structure factor, which normally is characteristic for the curves obtained with amorphous substances was observed for the Mn74Si26 melt. With the Mn33.5Si66.5 melt, however, this feature cold not be observed. Since with this concentration no glass forming by melt spinning is possible, a correlation between the shape of the second maximum of a total structure factor and the glass forming ability of the corresponding melt is suggested.

Chemical Species Identification in an SEM by Changes in Emitted X-Ray Energies

1974 ◽  
Vol 32 ◽  
pp. 570-571
Author(s):  
R. H. Duff
Keyword(s):  
Species Identification ◽  
Valence Electron ◽  
Chemical Species ◽  
X Rays ◽  
Chemical Bonds ◽  
Small Shift ◽  
X Ray ◽  
Electron Transitions ◽  
Peak Energy ◽  
Chemical Combination

A material irradiated with electrons emits x-rays having energies characteristic of the elements present. Chemical combination between elements results in a small shift of the peak energies of these characteristic x-rays because chemical bonds between different elements have different energies. The energy differences of the characteristic x-rays resulting from valence electron transitions can be used to identify the chemical species present and to obtain information about the chemical bond itself. Although these peak-energy shifts have been well known for a number of years, their use for chemical-species identification in small volumes of material was not realized until the development of the electron microprobe.

Absolute Stereochemistry of (-)-Wieland-Miescher Ketone as Established by the X-ray Crystallographic and CD Exciton Chirality Methods

1992 ◽  
Vol 57 (7) ◽  
pp. 1459-1465 ◽  
Author(s):  
Nobuyuki Harada ◽  
Tatsuo Sugioka ◽  
Hisashi Uda ◽  
Takeo Kuriki
Keyword(s):  
Structure Analysis ◽  
Absolute Configuration ◽  
X Ray ◽  
The Absolute ◽  
Absolute Stereochemistry

The 8aR absolute stereochemistry of Wieland-Miescher ketone (-)-I was established by the X-ray structure analysis of its bis(4-bromobenzoate) derivatives (1R,6R,8aR)-(+)-IV and (1R,6S,8aR)-(-)-V. The absolute configuration of (-)-I was corroborated further by the application of the CD exciton chirality method to bis(4-bromobenzoates) (+)-IV and (-)-V.

scholarly journals Preparative-scale HPLC Resolution of Metallacyclic η3-Allyltricarbonyliron Complexes and Determination of the Absolute Configuration by X-Ray Crystal Structure Analysis

1999 ◽  
Vol 23 (9) ◽  
pp. 578-579
Author(s):  
Rainer Schobert ◽  
Hermann Pfab ◽  
Jutta Böhmer ◽  
Frank Hampel ◽  
Andreas Werner
Keyword(s):  
Crystal Structure ◽  
Silica Gel ◽  
Structure Analysis ◽  
Absolute Configuration ◽  
Crystal Structure Analysis ◽  
Preparative Scale ◽  
X Ray ◽  
The Absolute

Racemates of (η3-allyl)tricarbonyliron lactone complex Fe(CO)3{η1:η3-C(O)XCH2CHCMeCH2} 1a (X = O) and (η3-allyl)tricarbonyliron lactam complex 2a (X = NMe) are resolved on a preparative scale by HPLC on cellulose tris(3,5-dimethylphenyl)carbamate/silica gel RP-8 and the absolute configuration of (-)-2a is determined by X-ray crystal structure analysis.

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