Exafs and Exelfs Study of the Structure of Pd-Ni-P Bulk Metallic Glasses

2000 ◽  
Vol 644 ◽  
Author(s):  
Faisal M. Alamgir ◽  
Himanshu Jain ◽  
David B. Williams ◽  
Gilles Hug ◽  
Ricardo B. Schwarz ◽  
...  
Keyword(s):  
Fine Structure ◽  
Metallic Glasses ◽  
Nearest Neighbor ◽  
Bulk Metallic Glasses ◽  
Weighted Average ◽  
Ternary Alloys ◽  
X Ray ◽  
Efficient Packing ◽  
X Ray Absorption ◽  
Nearest Neighbor Distances

AbstractWe have explored the short-range order around all three constituent atoms in (Pd-Ni)80P20 bulk metallic glasses (BMGs), a system that is a prototype for a whole class of BMG formers containing 80% transition metal and 20% metalloid. We have examined the changes in the nearest neighbor environments around the transition metals in (Pd-Ni)80P20 glasses using extended X-ray absorption fine structure (EXAFS) in comparison to their binary counterparts. We have done similar studies around the coordination of P using extended energy loss fine structure (EXELFS). The environment around the all the atoms in Pd60Ni20P20 and Pd30Ni50P20are very similar to those of the binary phosphides at the ends of the composition range. However, the (Pd-Ni)80P20 glasses are not simply solid solutions of the phases. The nearest neighbor distances of the metals are reduced in the ternary alloys with respect to those of the binary phosphides. The best glass former in this series, Pd40Ni40P20 is nearly isostructural to Pd30Ni50P20 but shows shorter distances at the 2nd and 3rd coordination shells, which we believe is due to more efficient packing in this glass. The metal environments in Pd40Ni40P20, on the other hand, are better described by a weighted average of those of Pd30Ni50P20 and Pd60Ni20P20.

scholarly journals Nearest Neighbor Distances in SrTiO 3 and BaTiO 3 from the Projection Analysis of the Extended X‐Ray Absorption Fine Structure

2020 ◽  
Vol 257 (7) ◽  
pp. 1900621
Author(s):  
Alireza Bayat ◽  
Angelika Chassé ◽  
Reinhard Denecke ◽  
Stefan Förster ◽  
Paula Huth ◽  
...  
Keyword(s):  
Fine Structure ◽  
Nearest Neighbor ◽  
X Ray ◽  
Absorption Fine ◽  
Projection Analysis ◽  
X Ray Absorption ◽  
Nearest Neighbor Distances

Fluorescence Extended X-Ray Absorption Fine Structure Study on Local Structures of Rare-Earth-Doped InGaGdN

2016 ◽  
Vol 1133 ◽  
pp. 429-433
Author(s):  
Siti Nooraya Mohd Tawil ◽  
Shuichi Emura ◽  
Daivasigamani Krishnamurthy ◽  
Hajime Asahi
Keyword(s):  
Fine Structure ◽  
Rare Earth ◽  
Nearest Neighbor ◽  
Structure Study ◽  
Edge Structure ◽  
X Ray ◽  
Local Structures ◽  
Absorption Fine ◽  
X Ray Absorption

Local structures around gadolinium atoms in rare-earth (RE)-doped InGaGdN thin films were studied by means of fluorescence extended X-ray absorption fine structure (EXAFS) measured at the Gd LIII-edges. The samples were doped with Gd in-situ during growth by plasma-assisted molecular beam epitaxy (PAMBE). Gd LIII-edge EXAFS signal from the GaGdN, GdN and Gd foil were also measured as reference. The X-ray absorption near edge structure (XANES) spectra around Gd LIII absorption edge of InGaGdN samples observed at room temperature indicated the enhancement of intensities with the increase of Gd composition. Further EXAFS analysis inferred that the Gd atoms in InGaN were surrounded by similar atomic shells as in the case of GaGdN with the evidence indicating majority of Gd atoms substituted into Ga sites of InGaGdN. A slight elongation of bond length for the 2nd nearest-neighbor (Gd–Ga) of sample with higher Gd concentration was also observed.

Short Range Order Strucrures in Y-Pr-Ba-Cu-O System Studied by X-Ray Absorption Fine Structure (XAFS) Techniques

1990 ◽  
Vol 209 ◽  
Author(s):  
Y.H. Kao ◽  
A. Krol ◽  
Z.H. Ming ◽  
C.S. Lin ◽  
Y.L. Soo ◽  
...  
Keyword(s):  
Fine Structure ◽  
Local Structure ◽  
Short Range ◽  
Direct Evidence ◽  
Nearest Neighbor ◽  
Compound System ◽  
Local Distribution ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

ABSTRACTLocal structure around the constituent atoms in the compound system Y1-xPrxBa2CU3O7-y has been investigated by means of x-ray absorption fine structure (XAFS) techniques. By comparing the local structure in the compound x=1 with its counterpart x=0, the XAFS results provide a direct evidence that Pr has replaced Y in the material. The nearest-neighbor structure in the CuO2 planes seems to remain intact as × varies from 0 to 1, indicating that substitution of Pr for Y does not disturb the local distribution of holes in the CuO2 planes. We suggest that local disorder and distortions in the second-neighbor bonding configuration could be responsible for suppression of superconductivity with increasing Pr content in the system.

EFFECT OF HEAT TREATMENT ON MICROSTRUCTURE AND MAGNETOSTRICTIVE PROPERTY OF MELT-SPUN Fe85Ga15 RIBBONS

2013 ◽  
Vol 27 (30) ◽  
pp. 1350174 ◽  
Author(s):  
HAO LIU ◽  
HAIOU WANG ◽  
MENGXIONG CAO ◽  
WEISHI TAN ◽  
YANGGUANG SHI ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Fine Structure ◽  
High Resolution ◽  
Nearest Neighbor ◽  
Annealed Sample ◽  
X Ray Diffraction ◽  
X Ray ◽  
Absorption Fine ◽  
Melt Spun ◽  
X Ray Absorption

In order to study the microstructure of Fe – Ga alloy, Fe 85 Ga 15 ribbons prepared with different wheel velocity were studied by high resolution X-ray diffraction (HRXRD) and extend X-ray absorption fine structure (EXAFS). HRXRD patterns showed that only disordered A 2 phase was observed in as-cast Fe 85 Ga 15 alloy. A modified- DO 3 phase was detected in all of the melt spun samples. The HRXRD associated with EXAFS results indicated that Ga atoms were located as second-nearest neighbor along [100] orientation. A little DO 3 phase was found in ribbons annealed at 1000°C under 0.06 MPa Ar atmosphere. The result of magnetostriction measurement revealed that in the ribbon prepared with higher wheel velocity, more modified- DO 3 phase will enhance the magnetostriction. DO 3 phase in the annealed sample will deteriorate the magnetostrictive properties of Fe – Ga ribbons.

Characterization of the Structure of a Novel Refractory Alloy Glass – Ni60Nb37Sn3

2002 ◽  
Vol 754 ◽  
Author(s):  
Michelle L. Tokarz ◽  
Matt Daniels ◽  
John C. Bilello ◽  
Zofia Rek
Keyword(s):  
Radial Distribution ◽  
Metallic Glasses ◽  
Hard Sphere ◽  
Nearest Neighbor ◽  
Refractory Alloy ◽  
Scattering Data ◽  
Distribution Analysis ◽  
X Ray ◽  
Nearest Neighbor Distances

ABSTRACTBulk forms of Refractory Alloy Glasses (RAGs) of the composition Ni60Nb37Sn3 have recently been synthesized as part of a larger project for potential use in structural applications. Modeling efforts of such metallic glasses have traditionally involved the use of hard sphere models without regard to potential electron density fluctuations of individual components. X-ray characterization of these materials (in both reflection and transmission modes) provided scattering data necessary for subsequent radial distribution analysis, which gives structural information such as nearest neighbor distances and packing characteristics. A model radial distribution function (RDF) was constructed based upon a hard sphere space filling assumption and compared to the RDFs obtained from experimental scattering data. The experimental RDFs showed no difference from the model RDF within the limit of experimental error, with regard to nearest neighbor distances and coordination numbers of the first two nearest neighbors.Additionally, transmission mode scattering experiments from a white beam x-ray source (E = 2 to 40 keV) demonstrated a through thickness amorphous structure of 2mm thick samples. Converted line profiles from the two-dimensional diffraction patterns from this experiment also showed agreement with reflection mode experiments. Samples of Vitreloy-106 (Zr57Nb5Cu15.4Ni12.6Al10) of similar thicknesses were used as standards due to the well-known behavior of this particular class of metallic glasses.

The Local Structure of Molten CdBr2

2005 ◽  
Vol 60 (1-2) ◽  
pp. 81-84
Author(s):  
Hideaki Shiwakua ◽  
Yoshihiro Okamoto ◽  
Tsuyashi Yaita ◽  
Shinichi Suzuki ◽  
Kazuo Minato ◽  
...  
Keyword(s):  
Fine Structure ◽  
High Temperature ◽  
Local Structure ◽  
Molten Salts ◽  
Room Temperature ◽  
Nearest Neighbor ◽  
Structural Parameters ◽  
Molten State ◽  
X Ray ◽  
X Ray Absorption

The local structure of molten CdBr2 was investigated by high temperature X-ray absorption fine structure (XAFS) analysis. The quartz cell designed for hygroscopic high temperature molten salts was successfully used in the measurement. At room temperature the nearest neighbor Cd2+-Br− distance decreased from 2.71 Å in solid state to 2.60 Å in the molten state. The coordination number decreased from 6 to 4 on melting. The obtained structural parameters showed that (CdBr4)2− is predominant in molten CdBr2.

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