Ferroelectric Switching in Hybrid Molecular-Beam-Epitaxy-Grown BaTiO₃ Films

Journal Article · Sat Sep 20 00:00:00 UTC 2025 · Nano Letters

DOI:https://doi.org/10.1021/acs.nanolett.5c02650· OSTI ID:3022078

Manjeshwar, Anusha Kamath ^[1]; Yang, Zhifei ^[1]; Liao, Chin-Hsiang ^[1]; Wen, Jiaxuan ^[1]; Koester, Steven J. ^[1]; James, Richard D. ^[1]; Jalan, Bharat ^[1]

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

Molecular beam epitaxy (MBE) is a promising synthesis technique for both heterostructure growth and epitaxial integration of ferroelectric BaTiO₃. However, direct measurement of the remnant polarization (P_r) has not been previously reported in MBE-grown BaTiO₃ films. We report the in situ growth of an all-epitaxial SrRuO₃/BaTiO₃/SrRuO₃ heterostructure on Nb-doped SrTiO₃ (001) substrates by hybrid MBE using metal–organic precursors. This capacitor structure consisting of 16 nm SrRuO₃/40 nm BaTiO₃/16 nm SrRuO₃ shows hysteretic polarization–electric field (P–E) curves with P_r ∼ 15 μC cm^–2 at frequencies ranging from 500 Hz to 20 kHz, after isolating the intrinsic ferroelectric response from non-ferroelectric contributions using the Positive-Up-Negative-Down (PUND) method. We hypothesize that the asymmetry in switching behavior and current leakage has origins in structural defects. Furthermore, this work opens the door to defect-engineered ferroelectric BaTiO₃-based heterostructures grown by hybrid MBE for future electronic, photonic and spintronic applications.

• Research Organization: University of Minnesota, Minneapolis, MN (United States)
• Sponsoring Organization: Air Force Office of Scientific Research (AFOSR); Materials Research Science and Engineering Center (MRSEC); National Nanotechnology Coordinated Infrastructure (NNCI); USDOE; Vannevar Bush Faculty Fellowship
• Grant/Contract Number: SC0020211
• Other Award/Contract Number: FA9550-18-1-0294; FA9550-23-1-0085; FA9550-23-1-0093; N00014-19-1-2623; DMR-2011401; FA9550-25-1-0262; FA9550-23-1-0247; ECCS-2025124
• OSTI ID: 3022078
• Journal Information: Nano Letters, Journal Name: Nano Letters Journal Issue: 39 Vol. 25; ISSN 1530-6992; ISSN 1530-6984
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

SrRuO3 electrode
electrodes
epitaxy
heterostructures
hybrid molecular beam epitaxy
lead-free ferroelectric BaTiO3
oxides
polarization
polarization switching
thin films