Coexistence of metallic and nonmetallic properties in the pyrochlore Lu$_2$Rh$_2$O$_7$

摘要: 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 RW = 2.5. However, electric transport measurements present …