Investigation of PbTiO₃ thin films with reduced and re-oxidized treatment using Raman spectroscopy

Abstract

Investigations of the lattice dynamics of defects, such as oxygen vacancies, are important to understand the properties of PbTiO 3 and related materials. Herein polarized Raman spectra of epitaxial PbTiO 3 thin films with reduced and re-oxidized treatment were investigated. The oxygen-reduced spectrum displayed an additional mode related to oxygen vacancies, whereas the reoxidized spectrum was the same as the initial one. The oxygen vacancy content increases as the intensity of additional mode increases, while the intensity of the B 1 mode related to oxygen ions decreases. First-principles calculations of the phonon mode related to oxygen vacancies support the assignment of the additional mode.

Strong interaction between ferroelectric polarization and oxygen vacancy in BiFeO₃ thin film capacitors

“…In ferroelectric oxides, the influence of V O •• on the polarization and piezoelectric responses has been intensively studied, 5), 6) because V O •• is considered to cause fatigue 7) and imprint 8) owning to a strong interaction between ferroelectric polarization and V O •• . In Pb-based ferroelectrics volatilization of Pb occurs inevitably during a high-temperature synthesis 9) and drives a formation of V O •• .…”