Structure of superconducting Ca-intercalated bilayer Graphene/SiC studied using total-reflection high-energy positron diffraction. (February 2020)

• Record Type: Journal Article
• Authors: Endo, Y.; Fukaya, Y.; Mochizuki, I.; Takayama, A.; Hyodo, T.; Hasegawa, S.
• Is Part Of: Carbon. Volume 157(2020)
• Page Start: 857
• Page End: 862
• Publication Date: 2020-02
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2019.10.070
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: We have investigated the atomic structure of superconducting Ca-intercalated bilayer graphene on a SiC(0001) substrate using total-reflection high-energy positron diffraction. By comparing the experimental rocking-curves with ones calculated for various structural models using a full-dynamical theory, we have found that Ca atoms are intercalated in the graphene-buffer interlayer, rather than between the two graphene layers. From transport measurements, the superconducting transition was observed to be at T c onset = 4 K for this structure. This study is the first to clearly identify the relation between the atomic arrangement and superconductivity in Ca-intercalated bilayer graphene. Graphical abstract: Image 1