A Computational Investigation of the Barium Titanate Surface Interactions with Tert-Butylphosphonic Acid

Barium Titanate (BTO) is a ferroelectric material that has been widely researched and used in capacitor applications because of its large dielectric constant. To expand its range of applications, BTO has been successfully incorporated into composite nanoparticle matrices while still maintaining a high dielectric constant. A key step discovered in this manufacturing process is to coat BTO nanoparticles with phosphonic acid ligands to prevent particle aggregation and maximize the composite's dielectric constant. However, phosphonic acid ligands have been shown to interact with and modify metal oxide nanoparticle surfaces, potentially negatively impacting dielectric properties. In this presentation, we use density functional theory (DFT) calculations to report how tert-butylphosphonic acid bonds to the TiO2-terminated surface of bulk BTO. We present the binding energy associated with various tert-butylphosphonic acid/barium titanate interactions to determine the favorable binding modes, providing valuable insight into optimizing ferroelectric properties of the BTO composite material.