# Tuning the Magnetic Ordering Temperature of Hexagonal Ferrites by Structural Distortion Control

## TL;DR

This study demonstrates how atomic-scale structural distortions can enhance the magnetic ordering temperature in hexagonal ferrites, revealing new pathways for tuning magnetic properties through symmetry and lattice engineering.

## Contribution

The paper uncovers the relationship between structural distortion and magnetic ordering temperature, predicting and experimentally confirming a record-high TN in hexagonal ScFeO3.

## Key findings

- Larger structural distortion increases TN in hexagonal ferrites.
- A near-linear relation exists between TN and the tolerance factor.
- A power-law relation links TN and K3 distortion amplitude.

## Abstract

To tune the magnetic properties of hexagonal ferrites, a family of magnetoelectric multiferroic materials, by atomic-scale structural engineering, we studied the effect of structural distortion on the magnetic ordering temperature (TN). Using the symmetry analysis, we show that unlike most antiferromagnetic rare-earth transition-metal perovskites, a larger structural distortion leads to a higher TN in hexagonal ferrites and manganites, because the K3 structural distortion induces the three-dimensional magnetic ordering, which is forbidden in the undistorted structure by symmetry. We also revealed a near-linear relation between TN and the tolerance factor and a power-law relation between TN and the K3 distortion amplitude. Following the analysis, a record-high TN (185 K) among hexagonal ferrites was predicted in hexagonal ScFeO3 and experimentally verified in epitaxially stabilized films. These results add to the paradigm of spin-lattice coupling in antiferromagnetic oxides and suggests further tunability of hexagonal ferrites if more lattice distortion can be achieved.

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Source: https://tomesphere.com/paper/1901.11118