Magnetic topological materials show great potential applications in devices such as magnetic switches and magnetic storage. Therefore, it is crucial to synthesize new materials in this category and explore their physical characteristics in depth.

A recent joint study by Chinese researchers has revealed the relationship between the magnetic structure and physical properties of EuAgSb single crystals. Their research addresses key behaviors such as anomalous and topological Hall effects, contributing to our understanding of magnetic topological materials.

These findings were published online in the Journal of Alloys and Compounds.

In this study, associate researcher HAN Yuyan from Hefei Institutes of Physical Science of the Chinese Academy of Sciences, collaborated with associate professors KAN Xucai and GAO Wenshuai from Anhui University, and focused on EuAgSb single crystals. This is a type of europium-based compound known for its unique magnetic and electronic properties.

The presence of antimony (Sb) atoms in the material supports quasi-two-dimensional Dirac fermions, and the magnetic properties are modifiable through temperature and magnetic field adjustments.  This tuning also influences the material's electronic structure.

The team employed the flux method to grow high-quality EuAgSb crystals and conducted an extensive analysis of their magnetic, thermal, and electrical properties. Their experiments revealed that the material undergoes an antiferromagnetic transition at low temperatures, which can be suppressed by applying a stronger magnetic field. This transition was associated with an increase in magnetic entropy, as confirmed through heat capacity measurements.

Additionally, resistivity tests indicated that EuAgSb behaves as a metal, with resistivity increasing due to thermal fluctuations of the europium magnetic moments near the transition temperature. As the temperature decreased further, the resistivity dropped, indicating the formation of long-range order among the Eu moments.

Further analysis of the Hall effect showed significant anomalous Hall effect (AHE) and topological Hall effect (THE) below the transition temperature, both of which vanished upon increasing the temperature. These observations underscored the connection between the material's magnetic structure and its electrical properties.

The research demonstrated how variations in temperature and magnetic field can influence the magnetic structure of EuAgSb, thereby affecting its magnetic, thermal, and electrical properties. 

These findings enhanced our understanding of magnetic topological materials and laid the foundation for future development of devices based on such materials, according to the team.