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

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Molecular beam epitaxy (MBE) is a key technique for growing ferroelectric heterostructures.
• Direct measurement of remnant polarization (Pr) in MBE-grown BaTiO3 films has been lacking.
• Ferroelectric BaTiO3 is crucial for electronic, photonic, and spintronic devices.

Purpose of the Study:

• To report the in situ growth and characterization of epitaxial SrRuO3/BaTiO3/SrRuO3 heterostructures using hybrid MBE.
• To measure the remnant polarization (Pr) of MBE-grown BaTiO3 films.
• To explore the potential of these films for future device applications.

Main Methods:

• Hybrid MBE using metal-organic precursors for in situ growth.
• Fabrication of SrRuO3/BaTiO3/SrRuO3 capacitor structures.
• Ferroelectric characterization using Positive-Up-Negative-Down (PUND) method to isolate intrinsic response.

Main Results:

• Successful in situ growth of all-epitaxial SrRuO3/BaTiO3/SrRuO3 heterostructures.
• Observation of hysteretic polarization-electric field (P-E) curves with Pr ~ 15 μC cm⁻².
• Isolation of intrinsic ferroelectric response from non-ferroelectric contributions.

Conclusions:

• This work demonstrates the feasibility of achieving ferroelectric BaTiO3 films via hybrid MBE with measurable remnant polarization.
• Structural defects are hypothesized to cause asymmetry in switching behavior and leakage.
• The findings open avenues for defect-engineered ferroelectric heterostructures for advanced applications.