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Title: Coexistence of metallic and nonmetallic properties in the pyrochlore Lu2Rh2O7
Abstract

Transition metal oxides of the 4dand 5dblock 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 4d5Rh4+, 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 Lu2Rh2O7remains paramagnetic down to 2 K. Taken in combination, these three measurements suggest that Lu2Rh2O7is a correlated paramagnetic metal with a Wilson ratio ofRW = 2.5. However, electric transport measurements present a striking contradiction as the resistivity of Lu2Rh2O7is 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 Lu2Rh2O7may belong to the same novel class of non-Fermi liquids as the nonmetallic metal FeCrAs.

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PAR ID:
10154121
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
Nature Publishing Group
Date Published:
Journal Name:
npj Quantum Materials
Volume:
4
Issue:
1
ISSN:
2397-4648
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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