Atomic-scale spot structures and gap distributions on apical-fluorine cuprate superconductor Ba2Ca5Cu6O12 (O1−x, Fx)2 observed by STM/STS

Sugimoto A.

Shohara K.

Ekino T.

Watanabe Y.

Harada Y.

Mikusu S.

Tokiwa K.

Watanabe T.

Physica C: Superconductivity and its Applications

The atomic-scale surface electronic states on the multi-layered apical-fluorine cuprate superconductor Ba2Ca5Cu6O12 (O1−x, Fx)2 (Tc ≃ 70K) are investigated by using low temperature scanning tunneling microscopy/spectroscopy (STM/STS). The spatial gap distributions show the patch scale of ∼ 0.5 nm, which is quite shorter than the superconducting coherence length ∼ 2-3 nm of other cuprate superconducters of a few nm. The high-bias (∼ 1V) conductance map contains some characteristic spots with contrasts reverse to those at low bias, which are considered to be due to the charge unbalance of apical atoms such as O2− and F−.

Apical-fluorine cuprate

F0256

STM/STS

Physics [ 420 ]

eng

Elsevier B.V.

Copyright (c) 2009. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

This is not the published version. Please cite only the published version. この論文は出版社版でありません。引用の際には出版社版をご確認ご利用ください。

[ISSN] 0921-4534

[NCID] AA11461984

[DOI] 10.1016/j.physc.2009.12.004

[DOI] https://doi.org/10.1016/j.physc.2009.12.004