Mechanical properties of borophene films: A reactive molecular dynamics investigation

TL;DR

This study uses reactive molecular dynamics simulations to analyze the mechanical properties of various borophene films, revealing their anisotropic behavior, temperature dependence, and the influence of atomic vacancies on their stiffness and strength.

Contribution

It provides the first detailed molecular dynamics investigation of borophene's mechanical properties across different vacancy ratios and temperatures.

Findings

Young's modulus decreases with temperature.

Boron sheets show anisotropic mechanical response.

Room temperature fracture stress ranges from 12 N/m to 63 N/m.

Abstract

The most recent experimental advances could provide ways for the fabrication of several atomic thick and planar forms of boron atoms. For the first time, we explore the mechanical properties of five types of boron films with various vacancy ratios ranging from 0.1 to 0.15, using molecular dynamics simulations with ReaxFF force field. It is found that the Young's modulus and tensile strength decrease with increasing the temperature. We found that boron sheets exhibit an anisotropic mechanical response due to the different arrangement of atoms along the armchair and zigzag directions. At room temperature, 2D Young's modulus and fracture stress of these five sheets appear in the range 63 N/m and 12 N/m, respectively. In addition, the strains at tensile strength are in the ranges of 9, 11, and 10 percent at 1, 300, and 600 K, respectively. This investigation not only reveals the remarkable stiffness of 2D boron, but establishes relations between the mechanical properties of the boron sheets to the loading direction, temperature and atomic structures.