Structure of vacancy-ordered single-crystalline superconducting potassium iron selenide
文献类型：期刊论文
| 作者 | Zavalij, P ; Bao, W ; Wang, XF ; Ying, JJ ; Chen, XH ; Wang, DM ; He, JB ; Wang, XQ ; Chen, GF ; Hsieh, PY ; Huang, Q ; Green, MA |
| 刊名 | PHYSICAL REVIEW B
 |
| 出版日期 | 2011 |
| 卷号 | 83期号:13 |
| 关键词 | LAYERED QUATERNARY COMPOUND LIFEAS METAL |
| ISSN号 | 1098-0121 |
| 通讯作者 | Zavalij, P (reprint author), Univ Maryland, Dept Chem, College Pk, MD 20742 USA. |
| 中文摘要 | With single-crystal x-ray diffraction studies, we compare the structures of three samples showing optimal superconductivity: K0.775(4)Fe1.613(1)Se2, K0.737(6)Fe1.631(3)Se2, and Cs0.748(2)Fe1.626(1)Se2. All have an almost identical ordered vacancy structure with a (root 5 x root 5 x 1) supercell. The tetragonal unit cell, space group I4/m, possesses lattice parameters at 250 K of a = b = 8.729(2) angstrom and c = 14.120(3) angstrom, a = b = 8.7186(12) angstrom and c = 14.0853(19) angstrom, and at 295 K, a = b = 8.8617(16) angstrom and c = 15.304(3) angstrom for the three crystals, respectively. The structure contains two iron sites; one is almost completely empty while the other is fully occupied. There are similarly two alkali metal sites that are occupied in the range of 72.2(2)%-85.3(3)%. The inclusion of alkali metals and the presence of vacancies within the structure allows for considerable relaxation of the FeSe4 tetrahedron, compared with members of the Fe(Te, Se, S) series, and the resulting shift of the Se-Fe-Se bond angles to less distorted geometry could be important in understanding the associated increase in the superconducting transition temperature. The structure of these superconductors are distinguished from the structure of the nonsuperconducting phases by an almost complete absence of Fe on the (0 0.5 0.25) site, as well as lower alkali metal occupancy that ensures an exact Fe2+ oxidation state, which are clearly critical parameters in the promotion of superconductivity. |
| 收录类别 | SCI |
| 资助信息 | National Basic Research Program of China (973 Program) [2011CBA00112, 2010CB923000, 2009CB009100, 2007CB925001]; National Science Foundation of China [11034012, 10834013, 10874244, 10974254]; National Science Foundation of China; Ministry of Science and Technology of China; Chinese Academy of Sciences |
| 语种 | 英语 |
| 公开日期 | 2014-02-20 |
| 源URL | [http://ir.iphy.ac.cn/handle/311004/57811]  |
| 专题 | 物理研究所_所内人员在其他单位发表论文题录信息_所内人员在其他单位发表论文题录信息_期刊论文 |
| 推荐引用方式 GB/T 7714 | Zavalij, P,Bao, W,Wang, XF,et al. Structure of vacancy-ordered single-crystalline superconducting potassium iron selenide[J]. PHYSICAL REVIEW B,2011,83(13). |
| APA | Zavalij, P.,Bao, W.,Wang, XF.,Ying, JJ.,Chen, XH.,...&Green, MA.(2011).Structure of vacancy-ordered single-crystalline superconducting potassium iron selenide.PHYSICAL REVIEW B,83(13). |
| MLA | Zavalij, P,et al."Structure of vacancy-ordered single-crystalline superconducting potassium iron selenide".PHYSICAL REVIEW B 83.13(2011). |
入库方式： OAI收割
来源：物理研究所
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