Pressure-induced transitions in ferroelectric single-crystal PbZr_0.54Ti_0.46O₃

Abstract

Pressure-induced phase transitions in single-crystal PbZr_0.54Ti_0.46O₃ are investigated with high-pressure Raman scattering and x-ray single crystal and powder diffraction. The appearance of a Raman peak near 380 cm⁻¹ indicates a structural transition at 3 GPa. A second transition, driven by an soft optical phonon, occurs at 9 GPa. A third transition occurs above 27 GPa, accompanied by a large changes in the Raman spectrum and splitting of the (pseudo-cubic) (111) and (220) diffraction lines. We identify the transitions as a monoclinic (Cm) to rhombohedral (R3m) transition at 3 GPa, followed by a rhombohedral (R3m) to rhombohedral (R-3c) transition at 9 GPa, and a further symmetry-lowering transition at 27 GPa.

KEYWORDS:

• PZT single crystal
• structural transitions
• high-pressure
• Raman scattering
• x-ray diffraction

Funding

This work was sponsored by the Office of Naval Research under Grants N00014-02-1-0506, N00014-06-1-0166, N00014-12-1-1038, N00014-12-1-1045, and ONR: N00014-14-1-0561; the Capital/Department of Energy Alliance Center (CDAC, DE-NA-0002006), and the Natural Sciences and Engineering Research Concil of Canada (NSERC). This research was also supported by EFree, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under Award DESC0001057 (salary support for MA and MS); and MA acknowledges the Carnegie Canada Foundation. REC was also supported by the ERC Advanced Grant ToMCaT. Use of the Advanced Photon Source was supported by the U. S. Department of Energy under Contract No. DE-AC02-06CH11357.