Magnetism in purple bronze Li$_{0.9}$Mo$_6$O$_{17}$

TL;DR

This study uses muon spin relaxation to investigate the magnetic properties of Li$_{0.9}$Mo$_6$O$_{17}$ around its metal-insulator transition, highlighting disorder's role and ruling out a spin density wave state.

Contribution

It provides new insights into the magnetic behavior and disorder effects in Li$_{0.9}$Mo$_6$O$_{17}$ during the transition, excluding SDW formation.

Findings

Disorder plays a significant role in the transition.

No evidence of spin density wave state.

Muon relaxation rates indicate magnetic fluctuations.

Abstract

Muon spin relaxation measurements around the 25 K metal-insulator transition in Li$_{0.9}$Mo$_6$O$_{17}$ elucidate a profound role of disorder as a possible mechanism for this transition. The relaxation rate $1/T_1$ and the muon Knight shift are incompatible with the transition to a SDW state and thus exclude it.