Theoretical design of all-carbon networks with intrinsic magnetism

TL;DR

This paper proposes a universal first-principles design approach for creating intrinsic magnetic all-carbon materials by stacking graphene layers with acetylenic linkages, resulting in antiferromagnetic semiconductors.

Contribution

It introduces a novel design scheme inspired by Ovchinnikov's rule for all-carbon magnetic structures, validated through specific 2D and 3D examples.

Findings

Confirmed antiferromagnetic semiconducting behavior in designed structures

Demonstrated intralayer Ne9el and interlayer AFM couplings

Validated the design approach with first-principles calculations

Abstract

To induce intrinsic magnetism in the nominally nonmagnetic carbon materials containing only $s$ and $p$ electrons is an intriguing yet challenging task. Here, based on first-principles electronic structure calculations, we propose a universal approach inspired by Ovchinnikov's rule to guide us the design of a series of imaginative magnetic all-carbon structures. The idea is to combine the differently stacked graphene layers via the acetylenic linkages (-C$\equiv$C-) to obtain a class of two-dimensional (2D) and three-dimensional (3D) carbon networks. With first-principles electronic structure calculations, we confirm the effectiveness of this approach via concrete examples of double-layer ALBG-C14, triple-layer ALTG-C22, and bulk IALG-C30. We show that these materials are antiferromagnetic (AFM) semiconductors with intralayer N\'eel and interlayer AFM couplings. According to the above idea, our work not only provides a promising design scheme for magnetic all-carbon materials, but also can apply to other $\pi$-bonding network systems.