Direct observation of microstructures on superconducting single crystals of KxFe2−ySe2. (5th January 2017)

• Record Type: Journal Article
• Authors: Tanaka, Masashi; Takeya, Hiroyuki; Takano, Yoshihiko
• Is Part Of: Applied physics express. Volume 10:Number 2(2017)
• Publication Date: 2017-01-05
• Subjects: Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.7567/APEX.10.023101
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: Potassium-intercalated FeSe has been reported as a superconductor with a superconducting transition temperature ( T c ) of 30–48 K. However, the relationship among the surface morphology, compositional ratio, and crystal structure has not yet been clarified. This report directly reveals the correspondence among these three characteristics in single crystals with a T c onset of around 44 K by using a microsampling technique. Island-like parts on the surface of the crystals clearly exhibit the K x Fe2 Se2 structure with perfect FeSe layers, which is formed in conjunction with the K2 Fe4 Se5 phase. This results in the appearance of the T c onset at 44 K.