Unraveling Magnetic Structure in Zero Field—Single Crystal Neutron Diffraction Insights into EuRhGe₃

The EuTX₃ series, characterized by d-electron transition metals (T) and Si or Ge (X) with the tetragonal non-centrosymmetric BaNiSn₃-type crystal structure (space group I4mm), has emerged as a pivotal subject of study for understanding novel topological magnetic phases. Notably, recent neutron diffraction studies on EuNiGe₃ have revealed important insights into the hybrid skyrmion phases, marking a significant advancement in the field of topological magnetic states [1]. Expanding on the research in these systems, our study delves into another interesting compound of this family, EuRhGe₃. Its magnetic and transport properties reveal a complex magnetic phase diagram [2]. Interestingly, EuRhGe₃ shows a significant anomaly in magnetoresistance at the magnetic phase transitions [2].<br/>Using zero-field neutron diffraction on EuRhGe₃ single crystals, we aim to uncover its nuclear and magnetic structures. We have found no crystallographic structural changes down to 2 K. An antiferromagnetic transition is observed at T_N~11.5 K. The magnetic propagation vector is along the c-axis (0, 0, 0.8), forming a proper screw-type magnetic arrangement that propagates along the c-axis at 2K. The observed magnetic structure differs from other reported Eu-based ternary germanides [3, 4].<br/><br/>1. D. Singh et al., Nat Commun 14, 8050 (2023).<br/>2. A. Maurya et al., JMMM 401, 823 (2016).<br/>3. Fabrèges et al., PRB 93, 214414 (2016).<br/>4. T. Matsumura et al., JPSJ 91, 073703 (2022).