Non-linear Temperature Dependence of Resistivity in Single Crystalline Ag$_5$Pb$_2$O$_6$

TL;DR

This study investigates the electrical and magnetic properties of Ag_5Pb_2O_6, revealing unusual T^2 resistivity behavior and potential superconductivity below 48 mK, challenging existing theories on electron interactions.

Contribution

It reports the first observation of T^2 resistivity dependence up to room temperature and suggests possible superconductivity in Ag_5Pb_2O_6.

Findings

T^2 resistivity behavior observed up to room temperature

Detection of a phase transition with large diamagnetic signal

Potential superconductivity below 48 mK

Abstract

We measured electrical resistivity, specific heat and magnetic susceptibility of single crystals of highly conductive oxide Ag_5Pb_2O_6, which has a layered structure containing a Kagome lattice. Both the out-of-plane and in-plane resistivity show T^2 dependence in an unusually wide range of temperatures up to room temperature. This behavior cannot be accounted for either by electron correlation or by electron-phonon scattering with high frequency optic phonons. In addition, a phase transition with a large diamagnetic signal was found in the ac susceptibility, which strongly suggests the existence of a superconducting phase below 48 mK.