Site occupancy, magnetic moments, and elastic constants of off-stoichiometric Ni(2)MnGa from first-principles calculations
文献类型：期刊论文
| 作者 | Q. M. Hu ; C. M. Li ; R. Yang ; S. E. Kulkova ; D. I. Bazhanov ; B. Johansson ; L. Vitos |
| 刊名 | Physical Review B
 |
| 出版日期 | 2009 |
| 卷号 | 79期号:14 |
| 关键词 | density functional theory elastic constants elastic moduli ferromagnetic materials gallium alloys linear muffin-tin orbital method magnetic moments magnetomechanical effects manganese alloys martensitic transformations nickel alloys shape memory effects shear modulus stoichiometry shape-memory alloys ni-mn-ga martensitic-transformation phase-transformations potential model heusler alloys landau theory transition metals approximation |
| ISSN号 | 1098-0121 |
| 中文摘要 | The site occupancy and elastic modulus of off-stoichiometric Ni(2)MnGa alloys are investigated by the use of the first-principles exact muffin-tin orbital method in combination with coherent-potential approximation. The stable site occupancy at 300 K is determined by comparing the free energies of the alloys with different site-occupation configurations. It is shown that, for most of the off-stoichiometric Ni(2)MnGa, the "normal" site occupation is favorable, i.e., the excess atoms of the rich component occupy the sublattice(s) of the deficient one(s). Nevertheless, for the Ga-rich alloys, the excess Ga atoms have strong tendency to take the Mn sublattice no matter if Mn is deficient or not. Based on the determined site occupancy, the elastic moduli of the off-stoichiometric Ni(2)MnGa are calculated. We find that, in general, the bulk modulus increases with increasing e/a ratio (i.e., the number of valence electrons per atom). The shear moduli C(') and C(44) change oppositely with e/a ratio: C(') decreases but C(44) increases with increasing e/a. However, the Mn-rich Ga-deficient alloys deviate significantly from this general trend. The correlation of calculated elastic moduli and available experimental martensitic transformation temperatures (T(M)) demonstrates that the alloy with larger C(') than that of the perfect Ni(2)MnGa generally possesses lower T(M) except for Ni(2)Mn(1+x)Ga(1-x). |
| 原文出处 | |
| 公开日期 | 2012-04-13 |
| 源URL | [http://ir.imr.ac.cn/handle/321006/31971]  |
| 专题 | 金属研究所_中国科学院金属研究所 |
| 推荐引用方式 GB/T 7714 | Q. M. Hu,C. M. Li,R. Yang,et al. Site occupancy, magnetic moments, and elastic constants of off-stoichiometric Ni(2)MnGa from first-principles calculations[J]. Physical Review B,2009,79(14). |
| APA | Q. M. Hu.,C. M. Li.,R. Yang.,S. E. Kulkova.,D. I. Bazhanov.,...&L. Vitos.(2009).Site occupancy, magnetic moments, and elastic constants of off-stoichiometric Ni(2)MnGa from first-principles calculations.Physical Review B,79(14). |
| MLA | Q. M. Hu,et al."Site occupancy, magnetic moments, and elastic constants of off-stoichiometric Ni(2)MnGa from first-principles calculations".Physical Review B 79.14(2009). |
入库方式： OAI收割
来源：金属研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。