摘要
超导电性与铁磁性是两种相互对立的物理现象:超导体具有完全抗磁性,而铁磁体则产生自发磁化,两者很难共存.本文报道一种新型磁性超导体CsEuFe_4As_4,其晶体结构由FeAs超导层、非磁Cs单原子层以及磁性Eu单原子层沿c轴交替排列.实验测量表明,该材料在35.2K以下显示出大块超导电性.在15.5K以下,Eu^(2+)离子自旋呈铁磁排列,超导与之共存.因此,CsEuFe_4As_4是一种罕见的超导与铁磁共存的铁磁铁基超导体.
Superconductivity （SC） and ferromagnetism （FM） are in general antagonistic, which makes their coexistence very rare. Following our recent discovery of robust coexistence of SC and FM in RbEuFe4As4 （Liu et al. in Phys Rev B 93：214503, 2016）, here we report another example of such a coexistence in its sister com- pound CsEuFe4As4, synthesized for the first time. The new material exhibits bulk SC at 35.2 K and Eu2＋-spin ferro- magnetic ordering at 15.5 K, demonstrating that it is a new robust ferromagnetic superconductor.
基金
supported by the National Natural Science Foundation of China (11474252, 90922002 and 11190023)
the National Basic Research Program of China (2012CB821404)
