Structural and Magnetic Properties of LaCoO3/SrTiO3 Multilayers
Hongrui Zhang1, Jing Zhang1, Huaiwen Yang1
1Beijing National Laboratory for Condensed Matter & Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
ACS Applied Materials & Interfaces
|July 6, 2016
Summary
Multilayer thin films of lanthanum cobalt oxide (LaCoO3) and strontium titanate (SrTiO3) show enhanced magnetic properties compared to single layers. This study reveals a new method for tuning magnetism in perovskite oxide films.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Solid State Chemistry
Background:
- Perovskite oxide thin films, such as LaCoO3 (LCO), are of interest due to their unique electronic and magnetic properties.
- Understanding the interplay between structure and magnetism in multilayered systems is crucial for developing novel electronic devices.
Purpose of the Study:
- To investigate the structural and magnetic properties of LaCoO3/SrTiO3 (LCO/STO) multilayers with varying LCO thicknesses.
- To explore the influence of substrate choice (LSAT, STO, LAO) on the structural and magnetic behavior of LCO/STO multilayers.
- To demonstrate a novel approach for tuning the magnetic properties of perovskite oxide films.
Main Methods:
- Systematic study of LCO/STO multilayers with a fixed 4 nm STO layer and varied LCO thicknesses.
- Growth of multilayers on different substrates: Sr0.7La0.3Al0.65Ta0.35O3 (LSAT), SrTiO3 (STO), and LaAlO3 (LAO).
- Analysis of in-plane lattice constants and magnetic properties, including Curie temperature and saturation magnetization.
Main Results:
- LCO/STO multilayers grown on LSAT and STO substrates adopted the substrate's in-plane lattice constant.
- MLs on LAO exhibited in-plane lattice constants intermediate between those on LSAT and STO.
- Magnetic order in LCO/STO multilayers was significantly enhanced compared to LCO single layers.
- Ferromagnetic order persisted down to ~1.5 nm LCO thickness in MLs, whereas it vanished below ~6 nm in LCO single layers.
- Observed dark stripes, linked to magnetic order, remained clear in MLs but were vague in LCO single layers.
Conclusions:
- The magnetic properties of LaCoO3 can be significantly enhanced by forming multilayers with SrTiO3.
- The choice of substrate influences the structural properties and, consequently, the magnetic behavior of the multilayers.
- LCO/STO multilayers offer a promising route for tuning the magnetism of perovskite oxide films for potential applications.
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