Emergence of exchange bias field in FeS superconductor with cobalt-doping

Peng Yuan; Jia Han; Pengyu Cheng; Renhai Ma; Qiling Xiao; Jun-Yi Ge; Zhenjie Feng; Shixun Cao; Jincang Zhang; Wenlai Lu; Fei Chen

doi:10.1088/1361-648X/ac066c

Emergence of exchange bias field in FeS superconductor with cobalt-doping

J Phys Condens Matter. 2021 Jun 25;33(33). doi: 10.1088/1361-648X/ac066c.

Authors

Peng Yuan¹, Jia Han¹, Pengyu Cheng¹, Renhai Ma¹, Qiling Xiao¹, Jun-Yi Ge¹, Zhenjie Feng¹, Shixun Cao¹, Jincang Zhang¹, Wenlai Lu¹, Fei Chen^{1

2}

Affiliations

¹ Materials Genome Institute, Shanghai University, Shanghai, 200444, People's Republic of China.
² Shanghai Key Laboratory of High Temperature Superconductors, Shanghai, 200444, People's Republic of China.

PMID: 34049303
DOI: 10.1088/1361-648X/ac066c

Abstract

Among all the iron-based superconductors, the 11 series has the simplest layered structure but exhibits rich physical phenomenon. In this work, we have synthesized Fe_1-xCo_xS single crystals with tetragonal structure and studied their structure and magnetic properties. Magnetic susceptibility measurements indicate that the cobalt doping would suppress superconductivity and even introduce weak ferromagnetism besides antiferromagnetism. Scanning electron microscopy study reveals that the Co-doped samples exhibit intrinsic phase separation. Moreover, magnetic force microscopy measurement shows no magnetic domain in Fe_1-xCo_xS, indicating that neither phase is pure ferromagnetic. The coexistence of ferromagnetism and antiferromagnetism leads to the relatively large exchange bias field. Since the exchange bias effect has been widely used in the field of information storage, spin-valves, and magnetic tunnel junctions, our study provides another option for further application.

Keywords: crystal growth; exchange bias; iron-based superconductors; magnetic properties; strongly correlated systems.