Ferromagnetic and insulating behavior of LaCoO3 films grown on a (001) SrTiO3 substrate. A simple ionic picture explained ab initio

Abstract

This paper shows that the oxygen vacancies observed experimentally in thin films of LaCoO3 subject to tensile strain are thermodynamically stable according to ab initio calculations. By using DFT calculations, we show that oxygen vacancies on the order of 6 % forming chains perpendicular to the (001) direction are more stable than the stoichiometric solution. These lead to magnetic Co2+ ions surrounding the vacancies that couple ferromagnetically. The remaining Co3+ cations in an octahedral environment are non magnetic. The gap leading to a ferromagnetic insulating phase occurs naturally and we provide a simple ionic picture to explain the resulting electronic structure.

7 pages, 7 figures

References in corpus (7)

• The spin state transition in LaCoO${}_3$; revising a revision
• Strain-Induced Spin States in Atomically Ordered Cobaltites
• Oxygen vacancies in strained SrTiO${}_3$ thin films: formation enthalpy and manipulation
• Electron degeneracy and intrinsic magnetic properties of epitaxial Nb:SrTiO${}_3$ thin-films controlled by defects
• First-principles study of crystal and electronic structure of rare-earth cobaltites
• Pure spin current devices based on ferromagnetic topological insulators
• Excitonic magnetism in $d^6$ perovskites

Cited by in corpus (1)

• Competition of defect ordering and site disproportionation in strained LaCoO${}_3$ on SrTiO${}_3$(001)