Coexisting Surface Phases and Coherent One-Dimensional Interfaces on BaTiO₃(001)

Abstract

Coexistence of surface reconstructions is important due to the diversity in kinetic and thermodynamic processes involved. We identify the coexistence of kinetically accessible phases that are chemically identical and form coherent interfaces. Here, we establish the coexistence of two phases, c(2 × 2) and c(4 × 4), in BaTiO3(001) with atomically resolved Scanning Tunneling Microscopy (STM). First-principles thermodynamic calculations determine that TiO adunits and clusters compose the surfaces. We show that TiO diffusion results in a kinetically accessible c(2 × 2) phase, while TiO clustering results in a kinetically and thermodynamically stable c(4 × 4) phase. We explain the formation of domains based on the diffusion of TiO units. The diffusion direction determines the observed 1D coherent interfaces between c(2 × 2) and c(4 × 4) reconstructions. We propose atomic models for the c(2 × 2), c(4 × 4), and 1D interfaces.

Effects of ferroelectric polarization on surface phase diagram: Evolutionary algorithm study of theBaTiO3(001) surface

“…Interestingly, among over 1000 structures suggested by the evolutionary algorithm, the (2 × 1)-TiO model is the only one that satisfies both conditions of energy and symmetry. We thus attribute the formation of (2 × 1) reconstruction to the addition of TiO units, which is consistent with recent experimental observation of TiO adunits on the c(2×2) BTO(001) surface [36].…”

Catalysis on oxidized ferroelectric surfaces—Epitaxially strained LaTiO2N and BaTiO3 for photocatalytic water splitting

“…From our computed surface phase diagrams (see figures 4 and S1) and in agreement with other studies 13,41,42 , we however see that the transition potential between different types of adsorbates (clean, OH, O) slightly differs as a function of the bulk polarization. If we were to consider the large space of possible mixed and/or sub-monolayer adsorbate coverages, this implies that the adsorbate structure could differ significantly between surfaces with different bulk polarization.…”

New modalities of strain-control of ferroelectric thin films

“…Using first-principles thermodynamics [633], changes in surface composition and defect concentrations can be probed [634,635]. Epitaxial strain and interfacial effects are included directly, as are surface interactions with water and other molecules [636][637][638][639][640]. The influence of compositional disorder on temporal-and spatial-dependent dielectric response of relaxors and other ferroelectrics can now be modeled through molecular dynamics simulations of large supercells [641][642][643][644][645][646][647].…”