Phase stability of Ni-2(Mn1-xFex)Ga: A first-principles study
文献类型：期刊论文
| 作者 | H. B. Luo ; Q. M. Hu ; C. M. Li ; R. Yang ; B. Johansson ; L. Vitos |
| 刊名 | Physical Review B
 |
| 出版日期 | 2012 |
| 卷号 | 86期号:2 |
| 关键词 | ni-mn-ga shape-memory alloys field-induced strain magnetic-properties martensitic-transformation crystal-structures heusler alloys potential model ni2mnga approximation |
| ISSN号 | 1098-0121 |
| 中文摘要 | Ni-2(Mn1-xFex)Ga ferromagnetic shape memory alloy shows unusual composition-dependent martensitic transformation temperature (T-M), namely, T-M decreases with increasing e/a ratio. In hope of understanding this unusual behavior, we investigated the composition dependence of the heat of formation (H-f) and shear elastic modulus (C') of the cubic austenite as well as the stability of the five-layer modulated (5M) tetragonal martensite relative to the austenite, using first-principles exact muffin-tin orbital method in combination with coherent potential approximation. Our calculations demonstrated that H-f of the austenite increases with the Fe content x. C' increases slightly with x up to 0.05 but decreases thereafter. The composition dependence of both H-f and C' cannot fully account for the trend of T-M against x although such correlations have been proposed in literature for other Ni-Mn-Ga based alloys. The structure of 5M martensite phase of Ni-2(Mn1-xFex)Ga with 0 < x < 0.2 is determined by optimizing both the shear (changing c/a) and wavelike shuffle of atoms in (110) planes along [1 (1) over bar0] direction adopting the experimentally determined modulation function. The energy difference Delta E-AM between the austenite and 5M phases decreases with increasing x up to 0.05, following the lower Delta E-AM corresponding to lower T-M rule. However, with x larger than 0.05, Delta E-AM increases, against the experimental T-M similar to x behavior. We propose that, if taking the temperature effect and the spin-orbital coupling into account, the Delta E-AM similar to x curve might be altered and may explain the unusual composition dependence of Ni-2(Mn1-xFex)Ga. |
| 原文出处 | |
| 公开日期 | 2013-02-05 |
| 源URL | [http://ir.imr.ac.cn/handle/321006/60143]  |
| 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 | H. B. Luo,Q. M. Hu,C. M. Li,et al. Phase stability of Ni-2(Mn1-xFex)Ga: A first-principles study[J]. Physical Review B,2012,86(2). |
| APA | H. B. Luo,Q. M. Hu,C. M. Li,R. Yang,B. Johansson,&L. Vitos.(2012).Phase stability of Ni-2(Mn1-xFex)Ga: A first-principles study.Physical Review B,86(2). |
| MLA | H. B. Luo,et al."Phase stability of Ni-2(Mn1-xFex)Ga: A first-principles study".Physical Review B 86.2(2012). |
入库方式： OAI收割
来源：金属研究所
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