X-ray photoelectron diffraction study of relaxation and rumpling of ferroelectric domains in BaTi$O_3$(001)

Alexandre Pancotti (1) , Jiale Wang (1) , Peixuan Chen (2) , Ludovic Tortech (3, 4) , Cristian-Mihail Teodorescu (5) , Emmanouil Frantzeskakis (6) , Nicholas Barrett (1)

1 LENSIS - Laboratoire d'Etude des NanoStructures et Imagerie de Surface
2 JKU - Johannes Kepler University Linz [Linz]
3 SPCSI - Service de Physique et de Chimie des Surfaces et Interfaces
4 IPCM - Institut Parisien de Chimie Moléculaire
5 National Institute of Materials Physics, Magurele-Ilfov, Romania
6 SSOLEIL - Synchrotron SOLEIL

The surface of a ferroelectric BaTi$O_3$(001) single crystal was studied using synchrotron radiation induced x-ray photoelectron diffraction (XPD), x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and low-energy electron diffraction (LEED). AFM, XPS, and LEED show that the surface is BaO terminated with a (1×1) reconstruction. The Ba 4d, Ti 2p, and O 1s XPD results were compared with multiple scattering simulations for out-of-($P^+ , P^−$) and in-plane ($P^{in}$) polarizations using a genetic algorithm to determine atomic rumpling and interlayer relaxation. Linear combinations of the XPD simulations of the surface structure of each polarization state allow determination of the domain ordering. The best agreement with experiment is found for 55% $P^+$ , 38% $P^-$ , and 7% $P^{in}$. The rumpling is smaller at the surface than in the bulk, suggesting that both domain ordering and surface structural changes contribute to screening of the polarization.

Domains: Physics [physics]

Alexandre Pancotti, Jiale Wang, Peixuan Chen, Ludovic Tortech, Cristian-Mihail Teodorescu, et al.. X-ray photoelectron diffraction study of relaxation and rumpling of ferroelectric domains in BaTi$O_3$(001). Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2013, 87, pp.184116. ⟨10.1103/PhysRevB.87.184116⟩. ⟨cea-01477579⟩