Disappearance of Superconductivity in the Solid Solution between(Ca4Al2O6)(Fe2As2) and (Ca4Al2O6)(Fe2P2) Superconductors
Disappearance of Superconductivity in the Solid Solution between(Ca4Al2O6)(Fe2As2) and (Ca4Al2O6)(Fe2P2) Superconductors
复制标题
(Ca4Al2O6)(Fe2As2)和(Ca4Al2O6)(Fe2P2)超导体固溶体中超导性消失
DOI：
10.1021/ja305548s
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发表时间：
2012
影响因子：
15
通讯作者：
A. Iyo et al.
中科院分区：
文献类型：
--
作者：
P. M. Shirage;A. Iyo et al.
考察了两种钙钛矿型铁基超导体(Ca4Al2O6)(Fe2As2)和(Ca4Al2O6)(Fe2P2)的合金化效果。虽然这两种化学计量化合物的T_c分别为28K和17K，但它们的固溶体(Ca4Al2O6)(Fe2(As1-xPx)2)在x=0.50-0.95的较宽范围内不表现出超导电性。由此得到的相图与其他典型的铁基超导体如BaFe2(As，P)2和LaFe(As，P)O的相图完全不同，在非超导“母体”化合物中，当P取代As时，表现出超导电性。值得注意的是，非超导范围内的固溶体在50-100K的温度范围内表现出电阻率异常。这种行为使人想起在各种非超导母体化合物中常见的电阻率扭结，它标志着反铁磁/正交长程有序的开始。这种相似性表明，在目前的情况下，超导电性的抑制也有磁性和/或结构的起源。
The effect of alloying the two perovskite-type iron-based superconductors (Ca4Al2O6)(Fe2As2) and (Ca4Al2O6)(Fe2P2) was examined. While the two stoichiometric compounds possess relatively highTc’s of 28 and 17 K, respectively, their solid solutions of the form (Ca4Al2O6)(Fe2(As1–xPx)2) do not show superconductivity over a wide range fromx= 0.50 to 0.95. The resultant phase diagram is thus completely different from those of other typical iron-based superconductors such as BaFe2(As,P)2and LaFe(As,P)O, in which superconductivity shows up when P is substituted for As in the non-superconducting “parent” compounds. Notably, the solid solutions in the non-superconducting range exhibit resistivity anomalies at temperatures of 50–100 K. The behavior is reminiscent of the resistivity kink commonly observed in various non-superconducting parent compounds that signals the onset of antiferromagnetic/orthorhombic long-range order. The similarity suggests that the suppression of the superconductivity in the present case also has a magnetic and/or structural origin.