[13p-D221-1~14] 6.4 薄膜新材料

▼ [13p-D221-3] Conventional Exfoliation Method using a Hand Roller for Artificially-synthesized Mica Nanosheets with a Single Layer and Multi-layers in Wide-area and their Characterization.

〇(D)Mohammad Razzakul Islam¹、Masahiko Tomitori¹ (1.Japan Advanced Institute of Science and Technology)

キーワード：mica nanosheets, scanning Auger electron microscopy, Current voltage characteristics

Mechanical exfoliation of two-dimensional (2D) materials with adhesive tapes, followed by transfer them onto a substrate, has often been used to prepare single- or few-layer thick 2D samples. Although mechanical exfoliation techniques have led to understanding of novel physical phenomena of 2D materials, the exfoliation techniques fall short in terms of scalability. Here, we present a conventional approach to exfoliate single-layer or few-layer 2D nanosheets with wide area from 2D cleavable crystals using a polyurethane hand roller with a diameter of 20 mm. The sample was single-crystal oxide of artificially-synthesized phlogopite, one of mica family. Prior to transfer of the exfoliated nanosheets on Si substrates with/without 10-nm Au deposition via DC magnetron sputtering, the substrates were cleaned in an ozone cleaner with ultraviolet light irradiation to removed absorbates, and heated to extend the contact area at the interface between the mica nanosheet and the substrate by evaporation of water layer adsorbed on the substrate.
We determined the quantitative thickness of the few-layer mica nanosheets on Si substrate chiefly using scanning Auger electron microscopy/spectroscopy (SAM) in regard to the change of peak-to-peak intensities of the Auger electron. The Auger spectra showed distinct characteristic shapes and intensities according to the change of the number of layers of mica nanosheets. It has been shown that AES analysis can be used as a standard to determine their thickness in the range of 1 to 5 layers of mica film thickness, which has well coincided with the thickness measured by AFM.