Role of electron-lattice interactions in determining the magnetic structure of insulating manganites

Together with the strong electron-electron interactions, the role of the lattice distorsions turns out to be relevant in determining the specific magnetic structure of some insulating manganites. In particular, while a substantial Jahn-Teller distorsion is needed to account for the layered antiferromagnetic structure of LaMnO3, the observed collective shear of alternate ions in La0.5Ca0.5MnO3 is required to stabilize the CE magnetic structure of this compounds. The specific action of the lattice in stabilizing these peculiar magnetic orderings is thus clarified.