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Abstract Vertically aligned nanocomposite (VAN) thin films offer exceptional physical properties through diverse material combinations, providing a robust platform for designing complex nanocomposites with tailored performance. Considering materials compatibility issues, most of oxide‐metal VANs have focused on noble metals as the secondary phase in the oxide matrix. Here, an oxide‐metal hybrid metamaterials in the VAN form has been designed which combines ferroelectric BaTiO3(BTO) with two immiscible non‐noble metal elements of Co and Cu, resulting in a three‐phase BTO‐Co‐Cu (BTO‐CC) VAN film. This film exhibits a characteristic nanopillar‐in‐matrix nanostructure with three distinct types of nanopillar morphologies, i.e., Co‐rich cylindrical nanopillars, Cu‐Co‐nanolaminated Co rectangular nanopillars and Co‐Cu‐core–shell cylindrical nanopillars. Phase field modeling indicates the constructed structure is resulted from the interplay between thermochemical, chemomechanical, and interfacial energy driving forces. The strong structural anisotropy leads to anisotropic optical and magnetic properties, presenting potential as hyperbolic metamaterial (HMM) with transverse‐positive dispersion in the near‐infrared region. The inclusion of non‐noble Cu nanostructure induces surface plasmon resonance (SPR) in the visible region. Additionally, ferroelectric properties have been demonstrated in a BTO/BTO‐CC bilayer, confirming room‐temperature multiferroicity in the film. The complex three‐phase VANs offer a novel platform for exploring electro‐magneto‐optical coupling along vertical interfaces toward future integrated devices.
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Reducing leakage current and enhancing polarization in multiferroic 3D super-nanocomposites by microstructure engineering
Abstract Multiferroic materials have generated great interest due to their potential as functional device materials. Nanocomposites have been increasingly used to design and generate new functionalities by pairing dissimilar ferroic materials, though the combination often introduces new complexity and challenges unforeseeable in single-phase counterparts. The recently developed approaches to fabricate 3D super-nanocomposites (3D‐sNC) open new avenues to control and enhance functional properties. In this work, we develop a new 3D‐sNC with CoFe2O4(CFO) short nanopillar arrays embedded in BaTiO3(BTO) film matrix via microstructure engineering by alternatively depositing BTO:CFO vertically-aligned nanocomposite layers and single-phase BTO layers. This microstructure engineering method allows encapsulating the relative conducting CFO phase by the insulating BTO phase, which suppress the leakage current and enhance the polarization. Our results demonstrate that microstructure engineering in 3D‐sNC offers a new bottom–up method of fabricating advanced nanostructures with a wide range of possible configurations for applications where the functional properties need to be systematically modified.
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- PAR ID:
- 10369038
- Publisher / Repository:
- IOP Publishing
- Date Published:
- Journal Name:
- Nanotechnology
- Volume:
- 33
- Issue:
- 40
- ISSN:
- 0957-4484
- Page Range / eLocation ID:
- Article No. 405604
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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