paper

Evolution of magnetic phases and orbital occupation in (SrMnO3)n/(LaMnO3)2n superlattices

arXiv:0909.4335 · doi:10.1103/PhysRevB.80.140405

Abstract

The magnetic and electronic modifications induced at the interfaces in (SrMnO $_{3}$ ) $_{n}$ /(LaMnO $_{3}$ ) $_{2 n}$ superlattices have been investigated by linear and circular magnetic dichroism in the Mn L $_{2, 3}$ x-ray absorption spectra. Together with theoretical calculations, our data demonstrate that the charge redistribution across interfaces favors in-plane ferromagnetic (FM) order and $e_{g} (x^{2} - y^{2})$ orbital occupation, in agreement with the average strain. Far from interfaces, inside LaMnO $_{3}$ , electron localization and local strain favor antiferromagnetism (AFM) and $e_{g} (3 z^{2} - r^{2})$ orbital occupation. For $n = 1$ the high density of interfacial planes ultimately leads to dominant FM order forcing the residual AFM phase to be in-plane too, while for $n \geq 5$ the FM layers are separated by AFM regions having out-of-plane spin orientation.

accepted for publication as a Rapid Communication in Physical Review B