# Angular momentum compensation manipulation to room temperature of the ferrimagnet Ho$_{3-x}$Dy$_x$Fe$_5$O$_{12}$ detected by the Barnett effect

## TL;DR

This study demonstrates that the angular momentum compensation temperature in Ho-Dy ferrimagnet can be tuned to room temperature using the Barnett effect, enabling potential applications in magnetic devices through simple mechanical rotation.

## Contribution

It introduces a method to control and detect the angular momentum compensation temperature in Ho-Dy ferrimagnet using the Barnett effect, with the key finding that it can be set to room temperature.

## Key findings

- $T_A$ increases with Dy content.
- $T_A$ of Ho$_{1.5}$Dy$_{1.5}$Fe$_5$O$_{12}$ is at room temperature.
- Barnett effect can be used to explore angular momentum in magnetic materials.

## Abstract

We demonstrate that the angular momentum compensation temperature $T_A$, at which the net angular momentum in the sample disappears, can be controlled in Ho$_3$Fe$_5$O$_{12}$ by partially substituting Dy for Ho. The $T_A$ can be detected using the Barnett effect, by which mechanical rotation magnetizes an object due to spin-rotation coupling. We found that $T_A$ increases with the Dy content and clarified that the $T_A$ of Ho$_{1.5}$Dy$_{1.5}$Fe$_5$O$_{12}$ coincides with room temperature. The Barnett effect enables us to explore materials applicable to magnetic devices utilizing the angular momentum compensation only by rotating the powder sample at room temperature.