Structural phase transitions in AgTa0.5Nb0.5O 3 thin films

Y. Han, I. M. Reaney, R. L. Johnson-Wilke, M. B. Telli, D. S. Tinberg, I. Levin, D. D. Fong, T. T. Fister, S. K. Streiffer, S. Trolier-Mckinstry

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Abstract

Octahedral tilt transitions in epitaxial AgTa0.5Nb 0.5O3 (ATN) films grown on (001)p (where p=pseudocubic) oriented SrRuO3/LaAlO3 and LaAlO 3 substrates were characterized by electron diffraction and high resolution x-ray diffraction. It was found that the ATN films exhibited octahedral rotations characteristic of the Pbcm space group, similar to those seen in bulk materials; however, the temperature of the M3↔ M2 phase transition has been suppressed by ∼250 K due to the fact that the correlation length for rotations about cp was significantly reduced. The average off-center B-cation displacements, which signify the degree of long-range order for these local cation positions, were negligibly small compared to bulk materials, as inferred from the near-zero intensity of the 1/4(00l)p-type reflections. On cooling, pronounced ordering of B-cation displacements occurred at ≈60 K which is significantly lower compared to bulk (≈310 K). The onset of this ordering coincides with a broad maximum in relative permittivity as a function of temperature. It is believed that point and planar defects in thin ATN films disrupt the complex sequence of in-phase and antiphase rotations around cp thereby reducing the effective strength of interactions between the tilting and cation displacements.

Original languageEnglish (US)
Article number123517
JournalJournal of Applied Physics
Volume107
Issue number12
DOIs
StatePublished - Jun 15 2010

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All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Han, Y., Reaney, I. M., Johnson-Wilke, R. L., Telli, M. B., Tinberg, D. S., Levin, I., Fong, D. D., Fister, T. T., Streiffer, S. K., & Trolier-Mckinstry, S. (2010). Structural phase transitions in AgTa0.5Nb0.5O 3 thin films. Journal of Applied Physics, 107(12), [123517]. https://doi.org/10.1063/1.3447753