Thin films of ${\mathrm{PbTiO}}_3$, a classical ferroelectric, have been grown under tensile strain on single-crystal substrates of ${\mathrm{DyScO}}_3$. The films, of only 5 nm thickness, grow fully coherent with the substrate, as evidenced by synchrotron x-ray diffraction. A mapping of the reciprocal space reveals intensity modulations (satellites) due to regularly spaced polar domains in which the polarization appears rotated away from the substrate normal, characterizing a low-symmetry phase not observed in the bulk material. This could have important practical implications since these phases are known to be responsible for ultrahigh piezoelectric responses in complex systems.

• Received 25 December 2005

DOI:https://doi.org/10.1103/PhysRevLett.96.127602