# High throughput computational screening for 2D ferromagnetic materials: the critical role of anisotropy and local correlations

## TL;DR

This study uses computational screening to identify new 2D ferromagnetic materials, emphasizing the importance of anisotropy and local correlations, and predicts several candidates with high critical temperatures for experimental validation.

## Contribution

The paper introduces a high-throughput computational approach using the C2DB to discover novel 2D ferromagnetic materials considering anisotropy and correlations, expanding the known set of potential 2D magnets.

## Key findings

- Identified 12 new insulating ferromagnetic 2D materials.
- Predicted 5 candidates with critical temperatures higher than CrI3.
- Showed the impact of Hubbard U corrections on magnetic property predictions.

## Abstract

The recent observation of ferromagnetic order in two-dimensional (2D) materials has initiated a booming interest in the subject of 2D magnetism. In contrast to bulk materials, 2D materials can only exhibit magnetic order in the presence of magnetic anisotropy. In the present work we have used the Computational 2D Materials Database (C2DB) to search for new ferromagnetic 2D materials using the spinwave gap as a simple descriptor that accounts for the role of magnetic anisotropy. In addition to known compounds we find 12 novel insulating materials that exhibit magnetic order at finite temperatures. For these we evaluate the critical temperatures from classical Monte Carlo simulations of a Heisenberg model with exchange and anisotropy parameters obtained from first principles. Starting from 150 stable ferromagnetic 2D materials we find five candidates that are predicted to have critical temperatures exceeding that of CrI3. We also study the effect of Hubbard corrections in the framework of DFT+U and find that the value of U can have a crucial influence on the prediction of magnetic properties. Our work provides new insight into 2D magnetism and identifies a new set of promising monolayers for experimental investigation.