Presentation Information
[2P13]Structure analysis of (Pb, Bi)/Ge(111)-2×2 surface by using total-reflection high-energy positron diffraction (TRHEPD)
*Rintaro Takahashi1, Makoto Shoji1, Hyuma Miura1, Lars Konermann1, Izumi Mochizuki2, Ken Wada2, Toshio Hyodo2, Akari Takayama1,3 (1. Waseda University, 2. Institute of Materials Structure Science High Energy Accelerator Research Organization (KEK), 3. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University)
The study of the Rashba effect in surface superstructures is now being extended to single-atomic layer compounds. Theoretical predictions suggest that the Rashba effect occurs in (Pb, Bi)/Ge(111); since no actual structural determination has been performed, the accuracy of its band structure remains uncertain. In this study, we conducted a structural analysis using total-reflection high-energy positron diffraction (TRHEPD) for the (Pb, Bi)/Ge(111)-2×2 structure. We measured a series of diffraction patterns for a fixed incident azimuthal direction at various glancing angles and then plotted the diffraction intensity of the specular (00) spot as a function of angle, known as the rocking curve. The rocking curves obtained from the experiments were compared with those calculated from structural models in previous studies, revealing inconsistencies. This indicates that the actual structure deviates from the models. In the presentation, we will detail the fabrication process of the (Pb, Bi)/Ge(111)-2×2 structure, along with the results of the TRHEPD experiments and structural analysis.