STM/STS study of the local density of states in Cu doped Fe(Se, Te) superconductors. Issue 1 (1st August 2022)

• Record Type: Journal Article
• Authors: Sugimoto, Akira; Ishimitsu, Satoru; Ohtsubo, Hironori; Matsumoto, Kaito; Saito, Takeshi; Ekino, Toshikazu; Gabovich, Alexander M.
• Is Part Of: Journal of physics. Volume 2323:Issue 1(2022)
• Publication Date: 2022-08-01
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/2323/1/012010
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: The scanning tunnel microscopy/scanning tunnel spectroscopy (STM/STS) measurements of the local quasiparticle density of states (LDOS) in Cu x -Fe1.01- x Se0.4 Te0.6 ( x = 0.01-0.03) superconductors were carried out. Critical temperatures Tc decrease with increasing Cu-impurity doping level x . STM images show clear regular square arrangements of spots with the lattice spacing ~ 0.38 nm as well as the randomly distributed large spots, which are most possibly due to excess Fe atoms. While the STM image resembles that of non-doped Fe(Se, Te), the LDOS map shows various extra spot structures with bright (with higher magnitudes of dI / dV ) and dark (with lower magnitudes of dI / dV ) regions. With increasing x, the number of such spots grows proportionally, indicating that these spots most probably correspond to the dopant Cu atoms.