Anomalous electric conductions in KSbO3-type metallic rhenium oxides

TL;DR

This study synthesizes and characterizes KSbO3-type rhenium oxides, revealing unusual temperature-dependent resistivity behavior in three-dimensional metallic structures without strong electron correlations.

Contribution

It reports the synthesis and structural analysis of new rhenium oxides with unique resistivity temperature dependence, highlighting anomalous conduction properties.

Findings

Resistivity follows a non-standard $T^{1.6}$ dependence in most compounds.

Bi3Re3O11 exhibits an anomaly at 50 K in resistivity and magnetic susceptibility.

All compounds show metallic states with weak electron correlations.

Abstract

Single crystals of KSbO3-type rhenium oxides, La4Re6O$19, Pb6Re6O19, Sr2Re3O9 and Bi3Re3O11, were synthesized by a hydrothermal method. Their crystal structures can be regarded as a network of three-dimensional orthogonal-dimer lattice of edge-shared ReO6 octahedra. All of them exhibit small magnitude of Pauli paramagnetism, indicating metallic electronic states without strong electron correlations. The resistivity of these rhenates, except Bi3Re3O11, have a temperature dependence of $rho(T)=\rho_{0}+AT^{n}$ $(n \approx 1.6)$ in a wide temperature range between 5 K and 300 K, which is extraordinary for three-dimensional metals without strong electron correlations. The resistivity of Bi3Re3O11 shows an anomaly around at 50 K, where the magnetic susceptibility also detects a deviation from ordinary Pauli paramagnetism.