Spin and orbital ordering in double-layered manganites

TL;DR

This paper presents a theoretical analysis of the phase diagram of double-layered manganites, explaining spin and orbital ordering phenomena and their dependence on doping, temperature, and lattice effects.

Contribution

It introduces a comprehensive theoretical model that accounts for orbital degeneracy, Coulomb interactions, and lattice coupling to explain experimental observations in double-layered manganites.

Findings

Orbital ordering explains spin structural changes with doping.

Bond-length dependence influences hopping and magnetic structure.

Temperature effects on neutron diffraction peaks are accounted for.

Abstract

We study theoretically the phase diagram of the double-layered perovskite manganites taking into account the orbital degeneracy, the strong Coulombic repulsion, and the coupling with the lattice deformation. Observed spin structural changes as the increased doping are explained in terms of the orbital ordering and the bond-length dependence of the hopping integral along $c$-axis. Temperature dependence of the neutron diffraction peak corresponding to the canting structure is also explained. Comparison with the 3D cubic system is made.