Evolution of superconductivity in isovalent Te-substituted KxFe2-ySe2 crystals
Toshinori Ozaki, Hiroyuki Takeya, Keita Deguchi, Satoshi Demura,, Hiroshi Hara, Tohru Watanabe, Denholme Saleem James, Hiroyuki Okazaki, Masaya, Fujioka, Takahide Yamaguchi, and Yoshihiko Takano
TL;DR
This study investigates how substituting Te for Se in KxFe2-ySe2 crystals affects their superconductivity, revealing a gradual decrease and eventual suppression of superconductivity with increasing Te content.
Contribution
It provides the first systematic phase diagram of Te substitution in KxFe2-ySe2, showing the suppression of superconductivity without structural transition.
Findings
Superconducting transition temperature decreases with Te content.
Superconductivity is completely suppressed at high Te substitution.
Lattice parameters expand systematically with Te substitution.
Abstract
We report the evolution of superconductivity and the phase diagram of the KxFe2-ySe2-zTez (z=0-0.6) crystals grown by a simple one-step synthesis. No structural transition is observed in any crystals, while lattice parameters exhibit a systematic expansion with Te content. The Tc exhibits a gradual decrease with increasing Te content from Tconset = 32.9 K at z = 0 to Tconset = 27.9 K at z = 0.5, followed by a sudden suppression of superconductivity at z = 0.6. Upon approaching a Te concentration of 0.6, the shielding volume fraction decreases and eventually drops to zero. Simultaneously, hump positions in r-T curve shift to lower temperatures. These results suggest that isovalent substitution of Te for Se in KxFe2-ySe2 crystals suppresses the superconductivity in this system.
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.