Tuning the Poisson's ratio of two-dimensional model network materials with application to 2D-silica bilayer structures.

A fundamental understanding of the elastic properties of 2D network structures is highly beneficial for research and applications of 2D materials. In this context, Poisson's ratio has been studied elaborately for different crystallographic structures of crystalline phases of bilayer silica structures. This paper focuses on the elastic structure–property relationship of crystalline and vitreous polymorphs of plane network materials. We generate defective crystalline network states and seven sets of disordered states, each with a different level of network heterogeneity, using a dual Monte Carlo bond switching algorithm. Firstly, uniaxial tensile deformation is applied to a model material in a two-dimensional framework, concentrating only on the in-plane network topologies. Secondly, uniaxial tensile deformation is applied to bilayer silica structures, considering the out-of-plane morphology of the material. Mechanical testing is performed using the athermal quasistatic deformation protocol, which allows one to study the influence of the network topology exclusively without any thermal disturbances. We show that manipulating the network heterogeneity allows one to directly tune the Poisson's ratio of the material, creating possibilities for novel mechanical applications. [Display omitted] [ABSTRACT FROM AUTHOR]