Among europium compounds, pressure induced valence transitions and/or intermediate valence states are often observed. In such systems, applying pressure of several GPa can drive a Eu valence from divalent to almost trivalent. Non-centrosymmetric EuRhGe₃ possesses magnetic Eu²⁺ ions and exhibits antiferromagnetic ordering at ∼11K at ambient pressure. Pressure resistant magnetic ordering and stable divalent Eu state have been reported in EuRhGe₃. Here, we study the pressure evolution of the Eu valence of EuRhGe₃ by high resolution x-ray absorption spectroscopy using the partial fluorescence yield method. Our study reveals a successive increase of the Eu valence with increasing pressure without any valence transition. The obtained mean Eu valence approaches ∼2.4 around 40GPa at 300K. The experimental data are also analyzed by a full multiplet configuration interaction calculation based on the single impurity Anderson model. The analysis reveals a decrease of the Eu 4f orbital occupation by applying pressure. Pressure evolution of the electronic structure studied by density functional theory suggests that the Rh ions have little contribution to the pressure evolution of the Eu valence, while it implies an active involvement of the Ge ions.

在铕化合物中，经常观察到压力诱导的价跃迁和/或中间价态。在这样的系统中，施加几个 GPa 的压力可以将 Eu 价从二价驱动到几乎三价。非中心对称 EuRhGe ₃具有磁性 Eu ²⁺离子，并在环境压力下在 ∼11K 时表现出反铁磁有序性。_{EuRhGe 3}中已经报道了耐压磁性有序和稳定的二价Eu状态。在这里，我们研究了 EuRhGe _{3的 Eu 价的压力演变}通过使用部分荧光产额法的高分辨率 X 射线吸收光谱。我们的研究揭示了随着压力的增加，Eu 化合价的连续增加而没有任何化合价跃迁。获得的平均 Eu 化合价在 300K 时接近 2.4 约 40GPa。实验数据还通过基于单杂质安德森模型的全多重配置相互作用计算进行分析。分析揭示了通过施加压力减少了 Eu 4 f轨道占据。密度泛函理论研究的电子结构的压力演化表明，Rh离子对Eu价的压力演化贡献很小，而这意味着Ge离子的积极参与。