Mechanical properties of freely suspended atomically thin dielectric layers of mica

TL;DR

This study investigates the elastic properties of atomically thin mica nanosheets, revealing high Young's modulus and low pre-strain, supporting their potential use in flexible electronics and nanocomposites.

Contribution

It provides the first detailed mechanical characterization of atomically thin mica layers, showing their elastic properties are comparable to bulk mica.

Findings

Young's modulus of 190 GPa across thicknesses

Ultrathin mica withstands reversible deformation up to tens of nanometers

Low pre-tension indicates minimal defects from exfoliation

Abstract

We have studied the elastic deformation of freely suspended atomically thin sheets of muscovite mica, a widely used electrical insulator in its bulk form. Using an atomic force microscope, we carried out bending test experiments to determine the Young's modulus and the initial pre-tension of mica nanosheets with thicknesses ranging from 14 layers down to just one bilayer. We found that their Young's modulus is high (190 GPa), in agreement with the bulk value, which indicates that the exfoliation procedure employed to fabricate these nanolayers does not introduce a noticeable amount of defects. Additionally, ultrathin mica shows low pre-strain and can withstand reversible deformations up to tens of nanometers without breaking. The low pre-tension and high Young's modulus and breaking force found in these ultrathin mica layers demonstrates their prospective use as a complement for graphene in applications requiring flexible insulating materials or as reinforcement in nanocomposites.