Intrinsic interaction between in-plane ferroelectric polarization and surface adsorption

Area of Science:

• Surface Science
• Materials Chemistry
• Computational Materials Science

Background:

• Ferroelectric surface chemistry is complex and not fully understood.
• Depolarization fields complicate surface chemistry when polarization is perpendicular.
• In-plane polarization offers a clearer route to study intrinsic surface properties.

Purpose of the Study:

• Investigate the impact of strain-induced in-plane polarization on molecular adsorption.
• Determine the dominant mechanism behind polarization-induced changes in adsorption energy.
• Explore the general applicability of findings to ferroelectric surfaces.

Main Methods:

• First-principles calculations.
• Studied adsorption of molecules on reduced rutile TiO2(110) surface.
• Analyzed the role of in-plane polarization and surface doping.

Main Results:

• Surface doping, driven by adsorbate-surface charge transfer, significantly alters adsorption energy.
• Charge transfer effectively screens long-range Coulomb interactions.
• Electrostatic interactions between polarized substrate and polar molecules are less critical.

Conclusions:

• Charge transfer is the primary driver of polarization-induced adsorption energy changes on ferroelectric surfaces.
• This mechanism is particularly relevant for ferroelectric surfaces lacking localized surface states.
• Findings provide fundamental insights into controlling surface chemistry via polarization.