Bi 3 MoM T O 9 (BMoM T O; M T , transition metals of Mn, Fe, Co and Ni) thin films with a layered supercell structure have been deposited on LaAlO 3 (001) substrates by pulsed laser deposition. Microstructural analysis suggests that pillar-like domains with higher transition metal concentration ( e.g. , Mn, Fe, Co and Ni) are embedded in the Mo-rich matrix with layered supercell structures. The layered supercell structure of the BMoM T O thin films accounts for the anisotropic multifunctionalities such as the magnetic easy axis along the in-plane direction, and the anisotropic optical properties. Ferroelectricity and ferromagnetism have been demonstrated in the thin films at room temperature, which confirms the multiferroic nature of the system. By varying the transition metal M T in the film, the band gaps of the BMoM T O films can be effectively tuned from 2.44 eV to 2.82 eV, while the out-of-plane dielectric constant of the thin films also varies. The newly discovered layered nanocomposite systems present their potential in ferroelectrics, multiferroics and non-linear optics.
Integration of highly anisotropic multiferroic BaTiO 3 –Fe nanocomposite thin films on Si towards device applications
Integration of highly anisotropic multiferroic thin films on silicon substrates is a critical step towards low-cost devices, especially high-speed and low-power consumption memories. In this work, an oxide–metal vertically aligned nanocomposite (VAN) platform has been used to successfully demonstrate self-assembled multiferroic BaTiO 3 –Fe (BTO–Fe) nanocomposite films with high structural anisotropy on Si substrates. The effects of various buffer layers on the crystallinity, microstructure, and physical properties of the BTO–Fe films have been explored. With an appropriate buffer layer design, e.g. SrTiO 3 /TiN bilayer buffer, the epitaxial quality of the BTO matrix and the anisotropy of the Fe nanopillars can be improved greatly, which in turn enhances the physical properties, including the ferromagnetic, ferroelectric, and optical response of the BTO–Fe thin films. This unique combination of properties integrated on Si offers a promising approach in the design of multifunctional nanocomposites for Si-based memories and optical devices.
- Publication Date:
- NSF-PAR ID:
- 10226856
- Journal Name:
- Nanoscale Advances
- Volume:
- 2
- Issue:
- 9
- Page Range or eLocation-ID:
- 4172 to 4178
- ISSN:
- 2516-0230
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Publisher's Version of Record
- https://doi.org/10.1039/d0na00405g
