Magnetism and superconductivity in Eu(Fe1-xNix)As2 (x =0, 0.04)

• 来源期刊: 中国科学:物理学 力学 天文学（英文版）
• 年，卷（期）: 2018,（12）
• 页码范围: 37-44
• 页数: 8页
• 语种: 英文

摘要

We report Eu-local-spin magnetism and Ni-doping-induced superconductivity (SC) in a 112-type ferroarsenide system Eu(Fet-xNix)As2.The non-doped EuFeAs2 exhibits two primary magnetic transitions at ～100 and ～40 K,probably associated with a spin-density-wave (SDW) transition and an antiferromagnetic ordering in the Fe and F-Eu sublattices,respectively.Two additional successive transitions possibly related to Eu-spin modulations appear at 15.5 and 6.5 K.For the Ni-doped sample with x =0.04,the SDW transition disappears,and SC emerges at Tc =17.5 K.The Eu-spin ordering remains at around 40 K,followed by the possible reentrant magnetic modulations with enhanced spin canting.Consequently,SC coexists with a weak spontaneous magnetization below 6.2 K in Eu(Fe0.96Ni0.04)As2,which provides a complementary playground for the study of the interplay between SC and magnetism.