Distinct topological Hall responses in CeCu$_2$-type EuZn$_2$ and EuCd$_2$ films

TL;DR

This study reports the successful growth of EuZn$_2$ films with CeCu$_2$-type structure and reveals distinct topological Hall effects compared to EuCd$_2$, highlighting EuZn$_2$ as a unique platform for magnetic domain boundary studies.

Contribution

First demonstration of EuZn$_2$ film growth via molecular beam epitaxy and identification of its unique topological Hall response compared to EuCd$_2$.

Findings

EuZn$_2$ exhibits a simpler topological Hall effect than EuCd$_2$.

The topological Hall response in EuZn$_2$ is enhanced at the magnetic transition field.

EuZn$_2$ may serve as a model for studying magnetic domain boundary effects.

Abstract

Rare earth intermetallic compounds crystallized in AlB$_2$-type and its low-symmetry derivative CeCu$_2$-type structures potentially host diverse frustrated magnetic structures and rich magnetotransport phenomena. We report the film growth of CeCu$_2$-type EuZn$_2$ by molecular beam epitaxy and the observation of topological Hall responses highly contrastive to isostructural EuCd$_2$. While their magnetization curves are rather similar, the topological Hall effect observed in EuZn$_2$ is simpler, with the only one component enhanced at the magnetic transition field. EuZn$_2$ may be a unique system for studying the magnetic domain boundary effect on topological Hall responses among the CeCu$_2$-type rare-earth intermetallic compounds.