Charge ordering in doped manganese oxides: lattice dynamics and magnetic structure

TL;DR

This paper investigates charge ordering in half-doped manganites, analyzing its effects on lattice dynamics and magnetic structure, revealing a new antiferromagnetic phase linked to charge ordering phenomena.

Contribution

It introduces a model based on small polarons with strong repulsion to explain charge ordering and its impact on magnetic phases in doped manganese oxides.

Findings

Renormalization of sound velocity near T_{CO}

Discovery of a new antiferromagnetic phase induced by charge ordering

Connection between charge ordering and CE-type magnetic structure

Abstract

Based on the Hamiltonian of small polarons with the strong nearest neighbor repulsion, we have investigated the charge ordering phenomena observed in half-doped manganites R_{1/2}A_{1/2}MnO_3. We have explored possible consequences of the charge ordering phase in the half-doped manganites. First, we have studied the renormalization of the sound velocity around $T_{CO}$, considering the acoustic phonons coupled to the electrons participating in the charge ordering. Second, we have found a new antiferromagnetic phase induced by the charge ordering, and discussed its role in connection with the specific CE-type antiferromagnetic structure observed in half-doped manganites.