Perfect monolayers of the BaTiO3‐derived 2D oxide quasicrystals investigated by scanning tunneling microscopy and noncontact atomic force microscopy

Abstract

The atomic structure of the BaTiO 3 -derived 2D oxide quasicrystals (OQCs) is investigated using scanning tunneling microscopy (STM) and noncontact atomic force microscopy (nc-AFM). It is demonstrated that these extraordinary films can easily be prepared as single-phase monolayers on a Pt(111) support. From analyzing almost 20 000 atomic vertices, an extended statistical dataset of the OQC tiling is collected. It manifests that the OQC obeys the statistics of the Niizeki–Gähler tiling, which is a dodecagonal triangle–square–rhomb model system. The atomic structure shown by nc-AFM is identical to the contrast obtained in STM images. The results are discussed with respect to the existing structural models.