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Dynamical Diffraction Simulations in FePt—I

Published online by Cambridge University Press:  15 April 2011

Karen L. Torres ,
Richard R. Vanfleet  and
Gregory B. Thompson
Karen L. Torres
Affiliation:
Department of Metallurgical & Materials Engineering, The University of Alabama, 301 7th Avenue, 116 Houser Hall, Tuscaloosa, AL 35487-0202USA
Richard R. Vanfleet
Affiliation:
Department of Physics and Astronomy, Brigham Young University, N283 ESC, Provo, UT 84602USA
Gregory B. Thompson*
Affiliation:
Department of Metallurgical & Materials Engineering, The University of Alabama, 301 7th Avenue, 116 Houser Hall, Tuscaloosa, AL 35487-0202USA
*
Corresponding author. E-mail: gthompson@eng.ua.edu
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Abstract

A series of multislice simulations to quantify the effect of various degrees of order, composition, and thickness on the electron diffracted intensities were performed using the L10 FePt system as the case study. The dynamical diffraction studies were done in both a convergent electron beam diffraction and selected area electron diffraction condition. The L10 symmetry demonstrated some peculiar challenges in the simulation, in particular between the {111} plane normal and the ⟨111⟩ direction, which are not equivalent because of tetragonality. A hybrid weighting function atom of Fe-Pt was constructed to account for S < 1 or nonequiatomic compositions. This statistical approach reduced the complexity of constructing a crystal with the probability that a particular atom was at a particular lattice site for a given order parameter and composition. Considerations of accelerating voltage, convergent angle, and thermal effects are discussed. The simulations revealed significant differences in intensity ratios between films of various compositions but equivalent unit cell numbers and degree of order.

Keywords

order parameterelectron diffractionmultislice simulationsFePtthin films
Type
Materials Applications
Information
Microscopy and Microanalysis , Volume 17 , Issue 3 , June 2011 , pp. 398 - 402
Copyright
Copyright © Microscopy Society of America 2011

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References

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