Vortex phase transition and anisotropy behavior of optimized (Li1−xFexOH)FeSe single crystals. (15th September 2016)

• Record Type: Journal Article
• Authors: Yi, Xiaolei; Wang, Chunlei; Tang, Qingbin; Peng, Tao; Qiu, Yang; Xu, Junqi; Sun, Haibin; Luo, Yongsong; Yu, Benhai
• Is Part Of: Superconductor science & technology. Volume 29:Number 10(2016:Oct.)
• Publication Date: 2016-09-15
• Subjects: (Li1−xFexOH)FeSe superconductors -- vortex transition -- phase diagram -- anisotropy; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/0953-2048/29/10/105015
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: (Li1− x Fe x OH)FeSe single crystals have been successfully synthesized by a hydrothermal ion-exchange technique. We have carried out systematic research on the influence of the concentration of selenourea ( c m ) on the superconducting properties of (Li1− x Fe x OH)FeSe single crystals. The optimized specimens possess an onset superconducting transition temperature T c of up to 42 K obtained at c m = 0.8 mol l −1, and the corresponding residual resistivity ratio (RRR = ρ (300 K)/ ρ ( T c )) is estimated to be 11. The vortex liquid-to-glass phase transition has been discussed based on the collective pinning model. The large distance between the H g and H c2 lines, as well as the much narrower region of the pinned vortex-liquid phase, indicate a weak vortex-pinning ability in (Li1− x Fe x OH)FeSe single crystals. The big out-plane anisotropy behavior versus temperature has been explored according to the anisotropic Ginzburg–Landau theory, and the anisotropy factor Γ displays linear behavior towards temperature similar to that of SmFeAsO1− x F x superconductors.