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Theoretical investigation of the effects of composition and atomic disordering on the properties of Ni{sub 2}Mn(Al{sub 1-x}Ga{sub x}) alloy

Abstract

The influences of composition and Mn-Ga/Al disordering on the magnetic and elastic properties of the Ni{sub 2}Mn(Al{sub 1-x}Ga{sub x}) Heusler alloy are investigated by the use of the first-principles exact muffin-tin orbital method in combination with coherent-potential approximation. The transition temperature from the completely disordered B2 phase to the ordered L2{sub 1} phase, estimated by the use of Bragg-Williams-Gorsky approximation, is in excellent agreement with experiments. The site-occupancy in the partially disordered alloy is determined by comparing the free energies of the alloys with different site-occupation configurations. It is found that Mn atoms generally prefer to exchange with Al atoms for the alloy with low degree of disorder and low Ga concentration. With increasing degree of disorder and Ga concentration, Mn may exchange with Ga as well. The total magnetic moment of the completely ordered alloy exhibits a minimum around x = 0.7 due to the competition between the increasing magnetic moments of Mn atoms and the decreasing moments of Ni atoms with increasing x. For the partially disordered alloy, both total and local magnetic moments of Mn and Ni decrease linearly with increasing degree of disorder, and Ga atoms show significant magnetism. The shear moduli C' of the alloys  More>>
Publication Date:
Feb 15, 2011
Product Type:
Journal Article
Resource Relation:
Journal Name: Acta Materialia; Journal Volume: 59; Journal Issue: 3; Other Information: DOI: 10.1016/j.actamat.2010.10.023; PII: S1359-6454(10)00685-3; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.
Subject:
36 MATERIALS SCIENCE; APPROXIMATIONS; ATOMS; AUGMENTATION; CONFIGURATION; ELASTICITY; FREE ENERGY; HEUSLER ALLOYS; MAGNETIC MOMENTS; MAGNETISM; MUFFIN-TIN POTENTIAL; PHASE TRANSFORMATIONS; SHEAR; TRANSITION TEMPERATURE; ALLOYS; ALUMINIUM ALLOYS; CALCULATION METHODS; COPPER ALLOYS; COPPER BASE ALLOYS; CORROSION RESISTANT ALLOYS; ENERGY; MANGANESE ALLOYS; MECHANICAL PROPERTIES; PHYSICAL PROPERTIES; POTENTIALS; THERMODYNAMIC PROPERTIES; TRANSITION ELEMENT ALLOYS
OSTI ID:
21564573
Country of Origin:
United Kingdom
Language:
English
Other Identifying Numbers:
Journal ID: ISSN 1359-6454; ACMAFD; TRN: GB11R0081042381
Availability:
Available from http://dx.doi.org/10.1016/j.actamat.2010.10.023
Submitting Site:
GBN
Size:
page(s) 971-980
Announcement Date:
Jun 25, 2012

Citation Formats

Luo, H B, Li, C M, Applied Materials Physics, Department of Materials Science and Engineering, Royal Institute of Technology, Stockholm SE-100 44 (Sweden)], Hu, Q.M., E-mail: qmhu@imr.ac.cn, Yang, R, Johansson, B, Condensed Matter Theory Group, Physics Department, Uppsala University, Uppsala SE-75121 (Sweden), School of Physics and Optoelectronic Technology and College of Advanced Science and Technology, Dalian University of Technology, Dalian 116024 (China)], Vitos, L, Condensed Matter Theory Group, Physics Department, Uppsala University, Uppsala SE-75121 (Sweden), and Research Institute for Solid State Physics and Optics, Budapest H-1525, PO Box 49 (Hungary)]. Theoretical investigation of the effects of composition and atomic disordering on the properties of Ni{sub 2}Mn(Al{sub 1-x}Ga{sub x}) alloy. United Kingdom: N. p., 2011. Web. doi:10.1016/j.actamat.2010.10.023.
Luo, H B, Li, C M, Applied Materials Physics, Department of Materials Science and Engineering, Royal Institute of Technology, Stockholm SE-100 44 (Sweden)], Hu, Q.M., E-mail: qmhu@imr.ac.cn, Yang, R, Johansson, B, Condensed Matter Theory Group, Physics Department, Uppsala University, Uppsala SE-75121 (Sweden), School of Physics and Optoelectronic Technology and College of Advanced Science and Technology, Dalian University of Technology, Dalian 116024 (China)], Vitos, L, Condensed Matter Theory Group, Physics Department, Uppsala University, Uppsala SE-75121 (Sweden), & Research Institute for Solid State Physics and Optics, Budapest H-1525, PO Box 49 (Hungary)]. Theoretical investigation of the effects of composition and atomic disordering on the properties of Ni{sub 2}Mn(Al{sub 1-x}Ga{sub x}) alloy. United Kingdom. https://doi.org/10.1016/j.actamat.2010.10.023
Luo, H B, Li, C M, Applied Materials Physics, Department of Materials Science and Engineering, Royal Institute of Technology, Stockholm SE-100 44 (Sweden)], Hu, Q.M., E-mail: qmhu@imr.ac.cn, Yang, R, Johansson, B, Condensed Matter Theory Group, Physics Department, Uppsala University, Uppsala SE-75121 (Sweden), School of Physics and Optoelectronic Technology and College of Advanced Science and Technology, Dalian University of Technology, Dalian 116024 (China)], Vitos, L, Condensed Matter Theory Group, Physics Department, Uppsala University, Uppsala SE-75121 (Sweden), and Research Institute for Solid State Physics and Optics, Budapest H-1525, PO Box 49 (Hungary)]. 2011. "Theoretical investigation of the effects of composition and atomic disordering on the properties of Ni{sub 2}Mn(Al{sub 1-x}Ga{sub x}) alloy." United Kingdom. https://doi.org/10.1016/j.actamat.2010.10.023.
@misc{etde_21564573,
title = {Theoretical investigation of the effects of composition and atomic disordering on the properties of Ni{sub 2}Mn(Al{sub 1-x}Ga{sub x}) alloy}
author = {Luo, H B, Li, C M, Applied Materials Physics, Department of Materials Science and Engineering, Royal Institute of Technology, Stockholm SE-100 44 (Sweden)], Hu, Q.M., E-mail: qmhu@imr.ac.cn, Yang, R, Johansson, B, Condensed Matter Theory Group, Physics Department, Uppsala University, Uppsala SE-75121 (Sweden), School of Physics and Optoelectronic Technology and College of Advanced Science and Technology, Dalian University of Technology, Dalian 116024 (China)], Vitos, L, Condensed Matter Theory Group, Physics Department, Uppsala University, Uppsala SE-75121 (Sweden), and Research Institute for Solid State Physics and Optics, Budapest H-1525, PO Box 49 (Hungary)]}
abstractNote = {The influences of composition and Mn-Ga/Al disordering on the magnetic and elastic properties of the Ni{sub 2}Mn(Al{sub 1-x}Ga{sub x}) Heusler alloy are investigated by the use of the first-principles exact muffin-tin orbital method in combination with coherent-potential approximation. The transition temperature from the completely disordered B2 phase to the ordered L2{sub 1} phase, estimated by the use of Bragg-Williams-Gorsky approximation, is in excellent agreement with experiments. The site-occupancy in the partially disordered alloy is determined by comparing the free energies of the alloys with different site-occupation configurations. It is found that Mn atoms generally prefer to exchange with Al atoms for the alloy with low degree of disorder and low Ga concentration. With increasing degree of disorder and Ga concentration, Mn may exchange with Ga as well. The total magnetic moment of the completely ordered alloy exhibits a minimum around x = 0.7 due to the competition between the increasing magnetic moments of Mn atoms and the decreasing moments of Ni atoms with increasing x. For the partially disordered alloy, both total and local magnetic moments of Mn and Ni decrease linearly with increasing degree of disorder, and Ga atoms show significant magnetism. The shear moduli C' of the alloys are calculated with respect to both x and the degree of disorder. The results show that C' decreases with increasing x and degree of disorder. The dependence on composition and on the degree of disorder of the martensitic transition temperatures is discussed in terms of the calculated C'.}
doi = {10.1016/j.actamat.2010.10.023}
journal = []
issue = {3}
volume = {59}
place = {United Kingdom}
year = {2011}
month = {Feb}
}