Design of a Vertical Composite Thin Film System with Ultralow Leakage To Yield Large Converse Magnetoelectric Effect
MacManus-Driscoll, Judith L
ACS Applied Materials & Interfaces
American Chemical Society (ACS)
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Wu, R., Kursumovic, A., Gao, X., Yun, C., Vickers, M., Wang, H., Cho, S., & et al. (2018). Design of a Vertical Composite Thin Film System with Ultralow Leakage To Yield Large Converse Magnetoelectric Effect. ACS Applied Materials & Interfaces, 10 (21), 18237-18245. https://doi.org/10.1021/acsami.8b03837
Electric field control of magnetism is a critical future technology for low-power, ultrahigh density memory. However, despite intensive research efforts, no practical material systems have emerged. Interface-coupled, composite systems containing ferroelectric and ferri-/ferromagnetic elements have been widely explored, but they have a range of problems, for example, substrate clamping, large leakage, and inability to miniaturize. In this work, through careful material selection, design, and nanoengineering, a high-performance room-temperature magnetoelectric system is demonstrated. The clamping problem is overcome by using a vertically aligned nanocomposite structure in which the strain coupling is independent of the substrate. To overcome the leakage problem, three key novel advances are introduced: a low leakage ferroelectric, Na0.5Bi0.5TiO3; ferroelectric–ferrimagnetic vertical interfaces which are not conducting; and current blockage via a rectifying interface between the film and the Nb-doped SrTiO3 substrate. The new multiferroic nanocomposite (Na0.5Bi0.5TiO3–CoFe2O4) thin-film system enables, for the first time, large-scale in situ electric field control of magnetic anisotropy at room temperature in a system applicable for magnetoelectric random access memory, with a magnetoelectric coefficient of 1.25 × 10–9 s m–1.
magnetism, magnetoelectric, multiferroics, Na0.5Bi0.5TiO3, nanocomposites
We acknowledge funding from the Leverhulme Trust grant # RPG-2015-017, EPSRC grant EP/N004272/1, and EP/M000524/1.
Leverhulme Trust (RPG-2015-017)
External DOI: https://doi.org/10.1021/acsami.8b03837
This record's URL: https://www.repository.cam.ac.uk/handle/1810/278846