Transition metal oxides of the 4d and 5d block have recently become the targets of materials discovery, largely due to their strong spin–orbit coupling that can generate exotic magnetic and electronic states. Here, we report the high-pressure synthesis of Lu₂Rh₂O₇, a new cubic pyrochlore oxide based on 4d⁵ Rh⁴⁺, and characterizations via thermodynamic, electrical transport, and muon spin relaxation measurements. Magnetic susceptibility measurements reveal a large temperature-independent Pauli paramagnetic contribution, while heat capacity shows an enhanced Sommerfeld coefficient, γ = 21.8(1) mJ/mol-Rh K². Muon spin relaxation measurements confirm that Lu₂Rh₂O₇ remains paramagnetic down to 2 K. Taken in combination, these three measurements suggest that Lu₂Rh₂O₇ is a correlated paramagnetic metal with a Wilson ratio of R_W = 2.5. However, electric transport measurements present a striking contradiction as the resistivity of Lu₂Rh₂O₇ is observed to monotonically increase with decreasing temperature, indicative of a nonmetallic state. Furthermore, although the magnitude of the resistivity is that of a semiconductor, the temperature dependence does not obey any conventional form. Thus, we propose that Lu₂Rh₂O₇ may belong to the same novel class of non-Fermi liquids as the nonmetallic metal FeCrAs.

4 d和5 d块的过渡金属氧化物最近已成为发现材料的目标，这主要是由于它们具有很强的自旋-轨道耦合能力，可以产生奇特的磁性和电子态。在这里，我们报告高压合成Lu ₂ Rh ₂ O ₇，这是一种基于4 d ⁵ Rh ⁴⁺的新型立方烧绿石氧化物，并通过热力学，电传输和介子自旋弛豫测量进行表征。磁化率测量显示出很大的与温度无关的Pauli顺磁性成分，而热容显示出增强的Sommerfeld系数，γ  = 21.8（1）mJ / mol-Rh K ²。Muon自旋弛豫测量结果证实Lu ₂ Rh ₂ O ₇在低至2 K时仍保持顺磁性。这三个测量结果相结合，表明Lu ₂ Rh ₂ O ₇是相关的顺磁性金属，其Wilson比为R _W  = 2.5。然而，电传输测量存在着明显的矛盾，因为Lu ₂ Rh ₂ O ₇的电阻率观察到随着温度的降低单晶硅增加，这表明是非金属态。此外，尽管电阻率的大小是半导体的电阻率的大小，但是温度依赖性不服从任何常规形式。因此，我们提出Lu ₂ Rh ₂ O ₇可以与非金属金属FeCrAs属于同一类新的非费米液体。