2025 Volume 68 Issue 2 Pages 91-96
Total-reflection high-energy positron diffraction (TRHEPD) is a positron version of reflection high-energy electron diffraction (RHEED). Due to the electrostatic repulsion between the positive charge of the positron and the crystal potential of the material, the penetration depth of the incident positron beam is limited to a few layers of the material surface. In particular, total reflection occurs at low grazing incidence and the penetration depth is less than about 1 Å, which corresponds to the thickness of one atomic layer. Therefore, TRHEPD is useful for the structure determination of material surfaces and two-dimensional materials. In this paper, we report recent results of structure determination using TRHEPD (intercalated graphene and graphene quasicrystals), together with the characteristics of the TRHEPD technique.
