%0 Journal Article
%T Coexistence of metallic and nonmetallic properties in the pyrochlore Lu2Rh2O7
%J -
%D 2019
%R https://doi.org/10.1038/s41535-019-0148-1
%X Transition metal oxides of the 4d and 5d block have recently become the targets of materials discovery, largely due to their strong spin¨Corbit 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, ¦Ã£¿=£¿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 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
%U https://www.nature.com/articles/s41535-019-0148-1