Enormous enhancement of p-orbital magnetism and band gap in the lightly doped carbyne

Abstract

This paper presents a path to tailor adapted magnetic and electronic properties in carbyne.

Routines for the synthesis of carbyne with more than 6000 atoms

“…Most importantly, ferromagnetism of pristine short carbon chains has been observed up to at least 400K [17]. Several dopants have been proposed to enhance the magnetism of carbyne-based semiconductors with a local magnetic moment above 1.7µB [17,18]. The monoatomic structure makes carbyne an ideal candidate for studying the physics of edge magnetism, as it is much thinner than any unit cell thick nanowire or ultrathin zigzag strips of graphene [19,20].…”

“…In contrast to the favourable kink structure in short carbon chains [17,23,24], magnetism has not been observed in a ~6000 atom long carbon chain [25]. To induce magnetism in a long carbon chain, dopants from groups IV, V and VII should likely be required [17,18]. However, the dopants should be introduced carefully to avoid chain breakage or self-dissociation.…”

“…It is foreseeable that controlling the stability of doped carbyne will be much more challenging than for pure carbyne [18]. Unfortunately, there is no systematic routine that provides the theoretical input for optimising the chain length of carbyne regardless of whether the chain is doped or not, which hinders experimental bottom-up studies of edge magnetism.…”

“…For example, a ~6000 atoms long carbyne surrounded by CNT (over ~100000 atoms per unit cell) may not be a realistic task for DFT software [33]. To speed up the computational progress, using DFT software to calculate an infinitely long LCC with few atoms per unit cell is inevitably a popular option [18,34]. DFT methods are ideal for situations at 0 K [35].…”

A Simulation of the Effect of External and Internal Parameters on the Synthesis of a Carbyne with More than 6000 Atoms for Emerging Continuously Tunable Energy Barriers in CNT-Based Transistors

“…One year later, Chi Ho Wong et al succeeded in fabricating a ferromagnetic VDW-coupled free-standing carbon chain array with a length of ~100 atoms at room temperature assisted by the LCC model [ 13 ], where its ferromagnetism survives above 400 K. This observation is consistent with the argument of Shi et al that the VDW interaction can be used to stabilize carbyne. On the other hand, several dopants have been proposed to enhance the magnetism of carbyne-based semiconductors with a local magnetic moment above 1.7 µB [ 13 , 14 ].…”