Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
J Phys Condens Matter. 2010 Mar 31;22(12):125702. doi: 10.1088/0953-8984/22/12/125702. Epub 2010 Mar 11.
The SrFe(2)As(2 - x)P(x) (0.0 ≤ x ≤ 1.0) and CaFe(2)As(2 - y)P(y) (0.0 ≤ y ≤ 0.3) materials were prepared by a solid-state reaction method. X-ray diffraction measurements indicate that the single-phase samples can be successfully obtained for SrFe(2)As(2 - x)P(x) (0.0 ≤ x ≤ 0.8) and CaFe(2)As(2 - y)P(y) (0.0 ≤ y ≤ 0.3). Visible contraction of the lattice parameters is determined due to the relatively smaller radius of P ions in comparison with that of As. The spin-density-wave (SDW) instability associated with the tetragonal to orthorhombic phase transition is suppressed noticeably in both systems following the increase in P content. The highest superconducting transitions are observed at about 27 K in SrFe(2)As(1.3)P(0.7) and at about 13 K in CaFe(2)As(1.925)P(0.075), respectively. Structural analysis suggests that lattice contraction could notably affect the superconductivity in these materials.
采用固态反应法制备了 SrFe(2)As(2 - x)P(x) (0.0 ≤ x ≤ 1.0) 和 CaFe(2)As(2 - y)P(y) (0.0 ≤ y ≤ 0.3) 材料。X 射线衍射测量表明，对于 SrFe(2)As(2 - x)P(x) (0.0 ≤ x ≤ 0.8) 和 CaFe(2)As(2 - y)P(y) (0.0 ≤ y ≤ 0.3)，可以成功获得单相样品。由于 P 离子的半径相对较小，与 As 相比，晶格参数明显收缩。随着 P 含量的增加，两个体系中与四方到正交相转变相关的自旋密度波（SDW）不稳定性明显受到抑制。在 SrFe(2)As(1.3)P(0.7)中观察到最高超导转变约为 27 K，在 CaFe(2)As(1.925)P(0.075)中观察到最高超导转变约为 13 K。结构分析表明，晶格收缩可能显著影响这些材料的超导性。
