Jahn-Teller distortion induced charge-ordering in CE phase of manganites

TL;DR

This paper investigates how Jahn-Teller distortions, rather than Coulomb repulsion, induce charge ordering in the CE phase of half-doped manganites, supported by quantitative calculations of charge disproportionation.

Contribution

It demonstrates that Jahn-Teller distortions are the primary cause of charge ordering in the CE phase, with detailed calculations showing less than 13% charge disproportionation.

Findings

Charge disproportionation is less than 13%.

Jahn-Teller effect causes charge ordering.

Weak Jahn-Teller effect may lead to negative charge-disproportionation.

Abstract

The charge order of CE phase in half-doped manganites is studied, based on an argument that the charge-ordering is caused by the Jahn-Teller distortions of MnO6 octahedra rather than Coulomb repulsion between electrons. The uantitative calculation on the ferromagnetic zigzag chain as the basic structure unit of CE phase within the framework of two-orbital double exchange model including Jahn-Teller effect is performed, and it is shown that the charge-disproportionation of Mn cations in the charge-ordered CE phase is less than 13%. In addition, we predict the negative charge-disproportionation once the Jahn-Teller effect is weak enough.