Hybrid MBE Route to Adsorption-Controlled Growth of BaTiO₃ Membranes with Robust Polarization Switching

Journal Article · Mon Dec 01 00:00:00 EST 2025 · Nano Letters

DOI:https://doi.org/10.1021/acs.nanolett.5c04999· OSTI ID:3022081

Choo, Sooho ^[1]; Varshney, Shivasheesh ^[1]; Shah, Jay ^[1]; Manjeshwar, Anusha Kamath ^[1]; Lee, Dong Kyu ^[1]; Mkhoyan, K. Andre ^[1]; James, Richard D. ^[1]; Jalan, Bharat ^[1]

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1. University of Minnesota, Minneapolis, MN (United States)

Freestanding ferroelectric membranes are promising for flexible electronics, nonvolatile memory, photonics, and spintronics, but their synthesis is challenged by the need for reproducibility with precise stoichiometric control. Here, we demonstrate the adsorption-controlled growth of single-crystalline, epitaxial BaTiO₃ films by hybrid molecular beam epitaxy (MBE) on a binary oxide sacrificial layer. Using a simple water-droplet lift-off method, we obtained submillimeter- to millimeter-sized membranes that retained crystallinity, as confirmed by high-resolution X-ray diffraction, and exhibited robust tetragonal symmetry, as verified by Raman spectroscopy. Impedance spectroscopy confirmed a high dielectric constant of ∼1340, reflecting the robust dielectric response of the membranes. Ferroelectric functionality was revealed by piezoresponse force microscopy (PFM) and further verified by polarization-electric field (P-E) loop measurements with Positive-Up-Negative-Down (PUND). The P-E loops exhibited a remnant polarization of ∼5 μC cm^–2 and a coercive field of ∼63 kV cm^–1. Furthermore, these results were interpreted in relation to c- and a-domain configurations.

• Research Organization: University of Minnesota, Minneapolis, MN (United States)
• Sponsoring Organization: Air Force Office of Scientific Research Multi University Research Initiative (AFOSR MURI); Materials Research Science and Engineering Center (MRSEC); National Nanotechnology Coordinated Infrastructure (NNCI); USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0020211; SC0023464
• Other Award/Contract Number: FA9550-18-1-0294; FA9550-23-1-0085; FA9550-25-1-0262; DMR-2011401; ECCS-2025124
• OSTI ID: 3022081
• Journal Information: Nano Letters, Journal Name: Nano Letters Journal Issue: 50 Vol. 25; ISSN 1530-6992; ISSN 1530-6984
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

Raman spectroscopy
adsorption-controlled growth
cation stoichiometry
epitaxy
ferroelectricity
freestanding oxide thin film
hybrid MBE
membranes
molecular beam epitaxy
oxides
polarization