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

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	Theoretical investigation of the effects of composition and atomic disordering on the properties of Ni(2)Mn(Al(1-x)Ga(x)) alloy
	H. B. Luo; C. M. Li; Q. M. Hu; R. Yang; B. Johansson; L. Vitos
	2011
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	59 期号:3 页码:971-980
摘要	The influences of composition and Mn-Ga/Al disordering on the magnetic and elastic properties of the Ni(2)Mn(Al(1-x)Ga(x)) Hensler 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(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. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	[luo, h. b.; li, c. m.; hu, q. m.; yang, r.] chinese acad sci, shenyang natl lab mat sci, inst met res, shenyang 110016, peoples r china. [li, c. m.; johansson, b.; vitos, l.] royal inst technol, dept mat sci & engn, se-10044 stockholm, sweden. [johansson, b.; vitos, l.] uppsala univ, condensed matter theory grp, dept phys, se-75121 uppsala, sweden. [johansson, b.] dalian univ technol, sch phys & optoelect technol, dalian 116024, peoples r china. [johansson, b.] dalian univ technol, coll adv sci & technol, dalian 116024, peoples r china. [vitos, l.] res inst solid state phys & opt, h-1525 budapest, hungary.;hu, qm (reprint author), chinese acad sci, shenyang natl lab mat sci, inst met res, 72 wenhua rd, shenyang 110016, peoples r china;qmhu@imr.ac.cn
关键词	Heusler Alloy First-principles Calculations Elastic Constants Martensitic Transformation Ni-mn-ga Shape-memory Alloys Ni2mnga Single-crystals Magnetic-field Heusler Alloys Martensitic-transformation Beta-phase Potential Model Transition Behavior
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文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/30574
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	H. B. Luo,C. M. Li,Q. M. Hu,et al. Theoretical investigation of the effects of composition and atomic disordering on the properties of Ni(2)Mn(Al(1-x)Ga(x)) alloy[J]. Acta Materialia,2011,59(3):971-980.
APA	H. B. Luo,C. M. Li,Q. M. Hu,R. Yang,B. Johansson,&L. Vitos.(2011).Theoretical investigation of the effects of composition and atomic disordering on the properties of Ni(2)Mn(Al(1-x)Ga(x)) alloy.Acta Materialia,59(3),971-980.
MLA	H. B. Luo,et al."Theoretical investigation of the effects of composition and atomic disordering on the properties of Ni(2)Mn(Al(1-x)Ga(x)) alloy".Acta Materialia 59.3(2011):971-980.