Open AccessToward Planar Iodine 2D Crystal Materials
Author(s) -
Xinyue Zhang,
Qingsong Huang
Publication year - 2021
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.1c00628
Subject(s) - semimetal , electron , atom (system on chip) , valence electron , dangling bond , octet , planar , chemistry , dirac (video compression format) , condensed matter physics , band gap , materials science , physics , quantum mechanics , hydrogen , computer graphics (images) , quark , computer science , embedded system , neutrino
Usually, the octet rule determines whether an elemental 2D material can only be set by one of the elements in groups IIIA-VA, whose outmost electrons can form hybridized orbits from an s-wave and a p-wave. The hybridized orbits can accommodate all of the outermost electrons and form robust σ bonds. As for the elements in VIA-VIIA, the outermost electrons seem too abundant to be accommodated in hybridized orbits. Here, we show a spd 2 hybridization rule, accommodating all of the outermost electrons of halogen elements. Each atom can be connected to a contiguous atom by a robust σ bond and carries one dangling unpaired electron, implying that the formation of a π bond is possible. One iodine atomic layer can be robustly locked by the σ bond, forming an iodiene sheet by spd 2 hybridized orbits. With application of compression strain, the π bond forms, and further compression drives the band inversion successively at the valence band and the conduction band. The appearance of Dirac points (arc or hoop) suggests that the transformation of a normal semimetal into a Dirac semimetal occurs.