Raman spectra of MOCVD-grown ferroelectric PbTiO(sub 3) thin films

摘要

Lead titanate (PbTiO(sub 3)) has been grown on a variety of substrates by using the metalorganic chemical vapor deposition (MOCVD) technique. The substrates employed included Si, GaAs, MgO, fused-quartz, sapphire, and KTaO(sub 3). Raman spectra from these heterostructures are presented. All of the films exhibited the strong, narrow spectral features characteristic of PbTiO(sub 3) perovskite-oxide crystals and indicative of high crystalline quality. The temperature behavior of the Raman modes, including the so-called ''soft-mode,'' was studied. A ''difference-Raman'' technique was used to distinguish the contributions of the PbTiO(sub 3) film and the KTaO(sub 3) single-crystal substrate.