A novel iron-based superconductor synthesized by the ion exchange technique. (1st April 2022)

• Record Type: Journal Article
• Authors: Hu, G B; Shi, M Z; Wang, W X; Zhu, C S; Luo, X G; Chen, X H
• Is Part Of: New journal of physics. Volume 24:Number 4(2022)
• Publication Date: 2022-04-01
• Subjects: superconductivity -- FeSe-based superconductor -- ion exchange -- nearly vacancy-free precursor; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/ac6319
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: The superconductivity of the FeSe-based superconductor is extremely sensitive to Fe vacancies in the FeSe plane. In order to reduce the formation of Fe vacancies in the FeSe plane, various low-temperature methods are developed. However, it is still complex and time consuming to control the Fe vacancies concentration. Here, a hybrid iron-based superconductor, Li0.21 Se0.05 (EG)0.26 FeSe (EG: ethylene glycol, C2 H6 O2 ), is synthesized by a solvothermal ion-exchange technique using a nearly vacancy-free precursor of (TBA)0.3 FeSe as the matrix. Bulk superconductivity with transition temperature ( T c ) of 30 K is confirmed by the characterization with the magnetic susceptibility and resistivity measurements. Compared with the pristine FeSe single crystal, x-ray photoelectron spectroscopy results show a decrease of the Fe valence, indicating that electron doping to FeSe plane accounts for the increase of the T c . Our result suggests that (TBA)0.3 FeSe, a nearly vacancy-free precursor with a large distance between the adjacent FeSe planes, is a good template candidate for the synthesis of other hybrid iron-based superconductors using the ion exchange technique.