Strain-Induced Spin States in Atomically Ordered Cobaltites

Abstract

Epitaxial strain imposed in complex oxide thin films by heteroepitaxy is recognized as a powerful tool for identifying new properties and exploring the vast potential of materials performance. A particular example is LaCoO3, a zero spin, nonmagnetic material in the bulk, whose strong ferromagnetism in a thin film remains enigmatic despite a decade of intense research. Here, we use scanning transmission electron microscopy complemented by X-ray and optical spectroscopy to study LaCoO3 epitaxial thin films under different strain states. We observed an unconventional strain relaxation behavior resulting in stripe-like, lattice modulated patterns, which did not involve uncontrolled misfit dislocations or other defects. The modulation entails the formation of ferromagnetically ordered sheets comprising intermediate or high spin Co3+, thus offering an unambiguous description for the exotic magnetism found in epitaxially strained LaCoO3 films. This observation provides a novel route to tailoring the electronic and magnetic properties of functional oxide heterostructures.

19 pages, 6 figures, including Supporting Information; Nano Letters published online (2012)

References in corpus (8)

• The spin state transition in LaCoO${}_3$; revising a revision
• Spin blockade, orbital occupation and charge ordering in La_(1.5)Sr_(0.5)CoO4
• Soft x-ray magnetic circular dichroism of LaCoO${}_3$, La${}_{0.7}$Ce${}_{0.3}$CoO${}_3$, and La${}_{0.7}$Sr${}_{0.3}$CoO${}_3$ films: Evidence for Co valency-dependent magnetism and magnetic anisotropy
• Structural effects on the spin-state transition in epitaxially strained LaCoO${}_3$ films
• Reversible strain effect on the magnetization of LaCoO3 films
• Ferromagnetic insulating state in tensile-strained LaCoO${}_3$ thin films
• Suppression of the ferromagnetic state in LaCoO3 films by rhombohedral distortion
• Suppression of spin-state transition in epitaxially strained LaCoO_{3}

Cited by in corpus (31)

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• Strain Control of Oxygen Vacancies in Epitaxial Strontium Cobaltite Films
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• Reversal of the lattice structure in SrCoOx epitaxial thin films studied by real-time optical spectroscopy and first-principles calculations
• Stretching Epitaxial La0.6Sr0.4CoO3-δ for Fast Oxygen Reduction
• Ionic Tuning of Cobaltites at the Nanoscale
• Near-Room Temperature Ferromagnetic Insulating State in Highly Distorted LaCoO2.5 with CoO5 Square Pyramids
• First-principles study of intermediate-spin ferrous iron in the Earth's lower mantle
• Exploiting symmetry-mismatch to control magnetism in a ferroelastic heterostructure
• Dimensionality Control of d-orbital Occupation in Oxide Superlattices
• Spin-Hall magnetoresistance in a low-dimensional magnetic insulator
• First-principles study of crystal and electronic structure of rare-earth cobaltites
• Role of Entropy and Structural Parameters in the Spin State Transition of LaCoO${}_3$
• Strain-induced atomic-scale building blocks for ferromagnetism in epitaxial LaCoO3
• DFT+DMFT study of spin-charge-lattice coupling in covalent LaCoO${}_3$
• Dynamics of anisotropic oxygen-ion migration in strained cobaltites
• Strain tuning of electronic structure in Bi4Ti3O12-LaCoO3 epitaxial thin films
• Competition of defect ordering and site disproportionation in strained LaCoO${}_3$ on SrTiO${}_3$(001)
• Spin State Disproportionation in Insulating Ferromagnetic LaCoO3 Epitaxial Thin Films
• Full control of Co valence in isopolar LaCoO3 / LaTiO3 perovskite heterostructures via interfacial engineering
• Structural, transport, optical and electronic properties of Sr${}_2$CoNbO${}_6$ thin films
• Structural, Electronic and Magnetic Properties of Bulk and Epitaxial LaCoO${}_3$ through Diffusion Monte Carlo
• Tunable Ferromagnetism in LaCoO3 Epitaxial Thin Films
• Nanoscale Sr${}_2$IrO${}_4$ Freestanding Thin-Films for Flexible Electronics
• Reversible Thermal Strain Control of Oxygen Vacancy Ordering in an Epitaxial La${}_{0.5}$Sr${}_{0.5}$CoO${}_{3-\delta }$ Film
• Room-Temperature Valence Transition in a Strain-Tuned Perovskite Oxide
• Surface and interface effects in oxygen deficient SrMnO${}_3$ thin films grown on SrTiO${}_3$
• Ferromagnetism of LaCoO${}_3$ films
• Ferromagnetic and insulating behavior of LaCoO3 films grown on a (001) SrTiO3 substrate. A simple ionic picture explained ab initio
• Electrically Tunable Spin Exchange Splitting in Graphene Hybrid Heterostructure
• Optical signatures of strain-induced ferromagnetism in LaCoO${}_3$ thin film