State Key Lab of Silicon Materials and Department of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China.
J Phys Condens Matter. 2011 Nov 23;23(46):464204. doi: 10.1088/0953-8984/23/46/464204. Epub 2011 Nov 3.
Superconductivity and ferromagnetism are two antagonistic cooperative phenomena, which makes it difficult for them to coexist. Here we demonstrate experimentally that they do coexist in EuFe₂(As(1-x)P(x))₂ with 0.2 ≤ x ≤ 0.4, in which superconductivity is associated with Fe 3d electrons and ferromagnetism comes from the long-range ordering of Eu 4f moments via Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions. The coexistence features large saturated ferromagnetic moments, high and comparable superconducting and magnetic transition temperatures, and broad coexistence ranges in temperature and field. We ascribe this unusual phenomenon to the robustness of superconductivity as well as the multi-orbital character of iron pnictides.
超导性和铁磁性是两种相互拮抗的协同现象，这使得它们很难共存。在这里，我们通过实验证明，在 EuFe₂(As(1-x)P(x))₂ 中（其中 0.2 ≤ x ≤ 0.4），它们确实共存，其中超导性与 Fe 3d 电子有关，铁磁性来自 Eu 4f 磁矩通过 Ruderman-Kittel-Kasuya-Yosida (RKKY) 相互作用的长程有序。共存的特征是具有大的饱和铁磁矩、高且相当的超导和磁转变温度以及在温度和场中的宽共存范围。我们将这种异常现象归因于超导性的稳健性以及铁磷化物的多轨道特性。
