Investigation of the magnetic properties of the perovskite Ba3PrRu2O9 using muon spin relaxation

The perovskites containing both ruthenium and lanthanide ions are of particular interest for the study of magnetic cooperative phenomena due to interactions between d and f electrons. We have performed the magnetic susceptibilities, specific heat, and neutron diffraction measurements on D20 at ILL for Ba3PrRu2O9 polycrystalline sample. It was found that a Pr4+ antiferromagnetic transition occurred at around 5 K and that Ba3PrRu2O9 showed magnetic behavior due to the Ru4+2O9 dimer in the higher temperature range. The magnetic susceptibility increases with a temperature above 200 K. However, this behavior cannot be explained by the dimer model. Powder neutron diffraction measurements at 2 K do not show clear magnetic brag peaks. In order to further clarify the magnetic ground state of Ba3PrRu2O9, we proposed to carry out µSR measurements on EMU/HiFi.

同时包含钌与镧系离子的钙钛矿（perovskites）因d电子与f电子间的相互作用，在磁协同现象研究中备受关注。本研究针对Ba₃PrRu₂O₉多晶样品，在ILL的D20谱仪上开展了磁化率、比热及中子衍射测试。实验结果表明，该样品在约5 K处出现Pr⁴+的反铁磁转变；在更高温度区间内，Ba₃PrRu₂O₉的磁行为源于Ru₄⁺₂O₉二聚体。该样品的磁化率在200 K以上随温度升高而增大，但该现象无法通过二聚体模型予以解释。在2 K温度下的粉末中子衍射测试未观测到清晰的磁布拉格峰（Bragg peaks）。为进一步阐明Ba₃PrRu₂O₉的磁基态，我们提议在EMU/HiFi上开展µSR（Muon Spin Relaxation/Resonance）测量。