title: Novel Two-Dimensional Silicon Dioxide with in-Plane Negative Poisson's Ratio.
abstract: Silicon dioxide or silica, normally existing in various bulk crystalline and amorphous forms, was recently found to possess a two-dimensional structure. In this work, we use ab initio calculation and evolutionary algorithm to unveil three new two-dimensional (2D) silica structures whose thermal, dynamical, and mechanical stabilities are compared with many typical bulk silica. In particular, we find that all three of these 2D silica structures have large in-plane negative Poisson's ratios with the largest one being double of penta graphene and three times of borophenes. The negative Poisson's ratio originates from the interplay of lattice symmetry and Si-O tetrahedron symmetry. Slab silica is also an insulating 2D material with the highest electronic band gap (>7 eV) among reported 2D structures. These exotic 2D silica with in-plane negative Poisson's ratios and widest band gaps are expected to have great potential applications in nanomechanics and nanoelectronics.
authors.affiliation: Center for Phononics and Thermal Energy Science, School of Physics Science and Engineering, Tongji University , 200092 Shanghai, P. R. China.|China-EU Joint Center for Nanophononics, School of Physics Science and Engineering, Tongji University , 200092 Shanghai, P. R. China.|Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University , 200092 Shanghai, P. R. China.
authors.forename: Zhibin
authors.identifier: 0000-0002-6843-381X
authors.initials: Z
authors.lastname: Gao
authors.affiliation: Center for High Pressure Science and Technology Advanced Research , Beijing 100193, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Dong
authors.affiliation: Center for Phononics and Thermal Energy Science, School of Physics Science and Engineering, Tongji University , 200092 Shanghai, P. R. China.|China-EU Joint Center for Nanophononics, School of Physics Science and Engineering, Tongji University , 200092 Shanghai, P. R. China.|Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University , 200092 Shanghai, P. R. China.
authors.forename: Nianbei
authors.initials: N
authors.lastname: Li
authors.affiliation: Center for Phononics and Thermal Energy Science, School of Physics Science and Engineering, Tongji University , 200092 Shanghai, P. R. China.|China-EU Joint Center for Nanophononics, School of Physics Science and Engineering, Tongji University , 200092 Shanghai, P. R. China.|Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University , 200092 Shanghai, P. R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Ren
keywords: 2D material with widest band gap; Two-dimensional material; crystal structure searching; in-plane negative Poisson’s ratio; silicon dioxide