Stress Induced Charge-Ordering Process in LiMn2O4

TL;DR

This paper investigates how stress induces charge ordering in LiMn2O4 spinel, revealing a Jahn-Teller effect-driven process with in-situ neutron diffraction showing electron localization and gradual lattice evolution.

Contribution

It uncovers the stress-induced charge-ordering mechanism in LiMn2O4 and details the lattice and charge evolution during the early transition phase.

Findings

Stress causes Mn charge ordering via Jahn-Teller effects.

Electron localization occurs at specific Mn sites during early transition.

Lattice and charge evolve gradually without first-order behavior.

Abstract

In this letter we report the stress induced Mn charge-ordering process in the LiMn2O4 spinel, evidenced by the lattice strain evolutions due to the Jahn-Teller effects. In-situ neutron diffraction, reveals that the initial stage of this process at low stress, indicating the eg electron localization at the preferential Mn sites during the early phase transition, as an underlying charge ordering mechanism in the charge-frustrated LiMn2O4. The initial stage of this transition exhibits as a progressive lattice and charge evolution, without showing a first-order behavior.