Abstract
We investigate the thermodynamic, magnetic, and electrical transport properties of a magnetic semimetal EuZnGe using single crystals grown from Eu-Zn flux in sealed tantalum tubes. Magnetic properties are found to be isotropic in the paramagnetic state while we observe an enhancement of in-plane magnetic susceptibility at the temperature near , suggesting an easy-plane anisotropy at low temperatures. Magnetic transition temperature is lower than as specific heat shows a peak at . We reveal the magnetic modulation along the axis by resonant x-ray scattering at Eu edge, which suggests competing magnetic interactions among Eu triangular-lattice layers. We observe a double-peak structure in the intensity profile along (0, 0, ) below , which is mainly composed of a dominant helical modulation with (0, 0, 0.4) coexisting with a secondary contribution from (0, 0, 0.5). We reproduce the intensity profile with a random mixture of five- and four-sublattice helices with spin rotation skipping due to hexagonal in-plane anisotropy. The metallic conductivity is highly anisotropic with the ratio exceeding 10 over the entire temperature range and additionally exhibits a sharp enhancement of at giving rise to , suggesting a coupling between out-of-plane electron conduction and the spiral magnetic modulations. In-plane magnetic field induces a spin-flop-like transition, where the peak disappears and an incommensurate peak of approximately 0.47 emerges, while the modulation retains a finite intensity. This transition correlates with nonmonotonic magnetoresistance and Hall resistivity, suggesting a significant interplay between electrons and spin structures through Ruderman-Kittel-Kasuya-Yosida interaction.
- Received 31 July 2022
- Accepted 6 September 2022
DOI:https://doi.org/10.1103/PhysRevMaterials.6.094410
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