Local structure in marginal glass forming Al-Sm alloy

Date

2010-08-01

Author

Kalay, Yunus Eren
Kramer, M. J.
Anderson, I. E.

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

190
views

0
downloads

The local structure in rapidly quenched Al(100-x)Smx (x = 8, 10, 11, and 12) and liquid Al89Sm11 has been investigated using a combination of transmission electron microscopy (TEM) and high-energy synchrotron X-ray diffraction (HEXRD). TEM analysis showed a featureless microstructure with diffuse scattering in rapidly quenched Al(100-x)Smx (x = 8, 10, 11, and 12) within the glass formation composition range under the bright field (BF) conditions. Total structure factor analysis of the liquid and as-quenched alloys revealed a pre-peak located well below the main amorphous peak and a distinct side peak. The presence of the pre-peak and the side peak is related to the formation of Sm rich medium range order (MRO) clusters in the liquid that is retained in the as-quenched alloys. Atomic structure models constructed using Reverse Monte Carlo (RMC) simulations from experimentally determined total structure factors and coupled with Voronoi Tessellation analysis indicated icosahedral and deformed bcc-like Voronoi polyhedron (VP) surrounding Al and Sm atoms, respectively. Sm atoms were found to be highly coordinated with Al atoms in the first shell neighborhood. The structural unit sizes corresponding to the extra broad peaks and the first shell neighborhood around Sm atoms have remarkable similarities with the high temperature metastable Al11Sm3 tetragonal phase. The existence of the Sm rich MRO clusters in the as-quenched state is believed to promote the high nucleation density of fcc-Al nanocrystals that form when the material is devitrified by acting as catalyst sites.

Subject Keywords

Mechanical Engineering, Materials Chemistry, Mechanics of Materials, General Chemistry, Metals and Alloys

URI

https://hdl.handle.net/11511/38130

Journal

INTERMETALLICS

DOI

https://doi.org/10.1016/j.intermet.2010.05.005

Collections

Department of Metallurgical and Materials Engineering, Article

Suggestions

OpenMETU
Core

Acoustic phonons scattering mobility and carrier effective mass in In6S7 crystals Qasrawi, A. F.; Hasanlı, Nızamı (Elsevier BV, 2006-12-21) Systematic dark electrical resistivity and Hall coefficient measurements have been carried out in the temperature range of 170-320 K on n-type In6S7 crystals. The analysis of the electrical resistivity and carrier concentration reveals the intrinsic type of conduction with an average energy band gap of similar to 0.75 eV The carrier effective masses of the conduction and valence bands were calculated from the intrinsic temperature-dependent carrier concentration data and were found to be 0.565m(0) and 2.020...
Optical dynamics of MgO/Ga4Se3S interface Qasrawi, A. F.; Abd-Alrazq, Mariam M.; Hasanlı, Nızamı (Elsevier BV, 2014-01-15) A new p-n interface made of p-type MgO as an optical window to the n-type Ga4Se3S crystals is investigated by means of optical reflectance, transmittance and absorbance in the incident light wavelength (k) range of 200-1100 nm. The reflectivity spectral analysis as a function of angle of incidence for MgO, Ga4Se3S and the Ga4Se3S/MgO layers revealed Brewster angles of 75 degrees, 80 degrees and 70 degrees with the corresponding dielectric constants of 13.93, 32.16 and eMgO 7: 55eGa(4)Se(3)S, respectively. T...
Annealing improvement on the localized states of plasma grown boron nitride film assessed through admittance measurements ÖZDEMİR, Orhan; Anutgan, Mustafa; Aliyeva-Anutgan, Tamila; Atilgan, Ismail; Katircioglu, Bayram (Elsevier BV, 2009-05-05) Boron nitride (BN) thin film was grown by plasma enhanced chemical vapor deposition (PECVD) technique and was investigated by UV-Visible transmission, Fourier transform infrared (FTIR) and ac conductance spectroscopies. Mainly the density of electronic localized states (D-it) at BN/Si interface was obtained by continuum and statistical models of ac conductance through an MIS structure (Al/BN film/Si). The origins of the electronic defects have been outlined and discussed within the frame of a nitrogen defic...
Size dependent stability and surface energy of amorphous FePt nanoalloy Akdeniz, Mahmut Vedat; Mehrabov, Amdulla (Elsevier BV, 2019-06-05) The effects of particle size (2-6 nm) and temperature (300-2700 K) on the stability and local structural evolutions of amorphous equiatomic FePt bulk/nanoalloys have been investigated by combining Embedded Atom Model (EAM) with classical molecular dynamics (MD) simulation method. The three dimensional (3D) atomic configuration of amorphous FePt NPs by means of Voronoi analysis reveals that, deformed bcc (d-bcc) and icosahedron (d-ico) type structures are most probable local atomic configurations for 2-6 nm ...
Structural and electrical properties of TlGa(SxSe1-x)(2) mixed crystals KARABULUT, ORHAN; Parlak, Mehmet; Mamedov, G. M. (Elsevier BV, 2007-01-21) Systematic investigations of crystal structure, electrical conductivity and photoconductivity have been carried out on the complete series of TlGa(SxSe1-x)(2) solid solutions. X-ray diffraction (XRD) analyses together with TREOR90 computer program have revealed that this compound shows different structural modifications at each composition. The possible charge transfer mechanisms have been investigated by performing temperature dependent electrical conductivity measurements in the temperature range of 100-4...

Citation Formats

Y. E. Kalay, M. J. Kramer, and I. E. Anderson, “Local structure in marginal glass forming Al-Sm alloy,” INTERMETALLICS, pp. 1676–1682, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/38130.