Antiferromagnetic Order in Epitaxial FeSe Films on SrTiO3

作者：Zhou Y; Miao L; Wang P; Zhu F F; Jiang W X; Jiang S W; Zhang Y; Lei B; Chen X H; Ding H F; Zheng Hao; Zhang W T; Jia Jin feng; Qian Dong^*; Wu D^*

来源：Physical Review Letters, 2018, 120(9): 097001.

DOI：10.1103/PhysRevLett.120.097001

Single monolayer FeSe film grown on a Nb-doped SrTiO3(001) substrate shows the highest superconducting transition temperature (T-C similar to 100 K) among the iron-based superconductors ( iron pnictides), while the TC value of bulk FeSe is only similar to 8 K. Although bulk FeSe does not show antiferromagnetic order, calculations suggest that the parent FeSe/SrTiO3 films are antiferromagnetic. Experimentally, because of a lack of a direct probe, the magnetic state of FeSe/SrTiO3 films remains mysterious. Here, we report direct evidence of antiferromagnetic order in the parent FeSe/SrTiO3 films by the magnetic exchange bias effect measurements. The magnetic blocking temperature is similar to 140 K for a single monolayer film. The antiferromagnetic order disappears after electron doping.

• 单位
  中国科学院; 上海交通大学; 空; 南京大学