# Tunability of Magnetic Anisotropy of Co on Two-Dimensional Materials by Tetrahedral Bonding

## TL;DR

This paper predicts that the magnetization orientation of cobalt on 2D materials like h-BN and graphene can be tuned by forming tetrahedral bonds that alter electronic hybridization, offering a new way to control magnetic properties.

## Contribution

It introduces a novel mechanism for tuning magnetic anisotropy via tetrahedral bonding-induced hybridization between sp$^3$ and d orbitals at 2D material interfaces.

## Key findings

- Reorientation of Co magnetization predicted on h-BN and graphene multilayers.
- Tetrahedral bonding transforms $\pi$-bonding to sp$^3$ hybridization.
- Charge density and band structure analyses confirm hybridization effects.

## Abstract

Pairing of $\pi$ electronic state structures with functional or metallic atoms makes them possible to engineer physical and chemical properties. Herein, we predict the reorientation of magnetization of Co on hexagonal BN (h-BN) and graphene multilayers. The driving mechanism is the formation of the tetrahedral bonding between sp$^3$ and d orbitals at the interface. More specifically, the intrinsic $\pi$-bonding of h-BN and graphene is transformed to sp$^3$ as a result of strong hybridization with metallic $d_{z^2}$ orbital. The different features of these two tetrahedral bondings, sp$^2$ and sp$^3$, are well manifested in charge density and density of states in the vicinity of the interface, along with associated band structure near the $\bar{K}$ valley. Our findings provide a novel approach to tailoring magnetism by means of degree of the interlayer hybrid bonds in 2D layered materials.