# Magnetic borophenes from evolutionary search

## TL;DR

This paper introduces a computational approach combining ab initio evolutionary algorithms and spin-polarized density functional theory to predict novel 2D magnetic materials, revealing a stable, magnetic borophene with unique properties.

## Contribution

It develops a new methodology for predicting 2D magnetic materials and discovers a stable, magnetic borophene with auxetic and magnetic properties simultaneously.

## Key findings

- Stable borophene is an antiferromagnetic semiconductor.
- Finite electron doping turns borophene into a half metal.
- Borophene exhibits out-of-plane negative Poisson's ratio.

## Abstract

A computation methodology based on ab initio evolutionary algorithms and the spin-polarized density functional theory was developed to predict two-dimensional (2D) magnetic materials. Its application to a model system borophene reveals an unexpected rich magnetism and polymorphism. A stable borophene with nonzero thickness was an antiferromagnetic (AFM) semiconductor from first-principles calculations, which can be further turned into a half metal by finite electron doping. In this borophene, the buckling and coupling among three atomic layers are not only responsible for the magnetism, but also result in an out-of-plane negative Poissons ratios under uniaxial tension, making it the first elemental material possessing auxetic and magnetic properties simultaneously.