Miakhs carbon allotropes: Three novel two-dimensional carbon allotropes with sp2 + sp3 hybridized network

Abstract

MIAKHs carbon allotropes with mixed sp2 + sp3 hybridized network have different properties. Here, three novel two-dimensional materials, namely the MIAKH20, MIAKH28, and MIAKH32 respectively, were predicted based on density functional theory (DFT). MIAKHs carbon allotropes belong to the P4mm (No. 99) space group and their structural properties, mechanical properties, mechanical and dynamical stability, and electronic properties are investigated in this work. The studies of mechanical properties indicate that these 2D materials are mechanically stable and also exhibit the isotropy behavior. In order to examine the thermal stability of these novel 2D materials, MD simulations with Tersoff potential are performed under a NVT ensemble. Our classical molecular dynamics calculations demonstrate that MIAKHs carbon allotropes are dynamically stable. The calculation of electronic band structure of MIAKH32 indicates that this structure is semiconductor with an indirect band gap of 0.53 eV, whereas band structure of MIAKH20, MIAKH28 structures indicates that both materials are metals. This research introduces new 2D polygon-like carbon allotropes and their excellent properties. The obtained results show that these three novel 2D materials can be candidate materials for applications in electromechanical systems and open a new viewpoint for the designs of novel 2D carbon allotropes based on highorder carbon rings.