[9p-W833-1~9] Surface Science Innovation by Positron Diffraction and High Performance Data Driven Science

[9p-W833-8] Structural analysis of bilayer-graphene intercalation compounds on SiC substrate by total-reflection high-energy positron diffraction

〇Akari Takayama¹, Yukihiro Endo², Yuki Fukaya³, Izumi Mochizuki⁴, Toshio Hyodo⁴, Shuji Hasegawa² (1.Waseda Univ., 2.Univ. Tokyo, 3.JAEA, 4.KEK-IMSS)

Keywords:TRHEPD, graphene

A superconductivity in graphite-intercalation compounds has been studied for long time. In particular, it is reported that superconducting transition in CaC₆ is observed at T_c = 11.5 K. Recently, Ca-intercalated bilayer graphene on SiC(0001) substrate also show superconducting transition at T_c = 2 K by in-situ four-point-probe resistivity measurement. However, the accurate structure is not clear yet, so the structure in previous studies is uncertain whether it is the thinnest CaC₆ or not. In this presentation, we demonstrate the result of the total internal reflection high-speed positron diffraction measurement in Ca-intercalated bilayer graphene. We will describe and discuss the Ca-intercalation process with the result of the rocking curve analysis based on the dynamical diffraction theory.