We report a series of new surface reconstructions on ${\mathrm{BaTiO}}_3(001)$ as a function of environmental conditions, determined via scanning tunneling microscopy and low energy electron diffraction. Using density functional theory calculations and thermodynamic modeling, we construct a surface phase diagram and determine the atomic structures of the thermodynamically stable phases. Excellent agreement is found between the predicted phase diagram and experiment. The results enable prediction of surface structures and properties under the entire range of accessible environmental conditions.

• Received 28 January 2008

DOI:https://doi.org/10.1103/PhysRevLett.101.036102