Volume 87, Issue 12, 15 June 2000
Index of content:
- DIELECTRICS AND FERROELECTRICITY (PACS 77)
87(2000); http://dx.doi.org/10.1063/1.373597View Description Hide Description
High dielectric constantceramics for 0.05, 0.08, and 0.11 were prepared and studied utilizing micro-Raman scattering and x-ray diffraction techniques. The modification in the lowest frequency phonon mode of pure with increasing content in these ceramics was assigned as Ta–Ti vibrations originating from the interaction between octahedra and or clusters. Raman spectra, in the range −200–900 °C, reveal a softening of this mode with increasing temperature followed by a structural transformation. A triclinic to monoclinic phase transition was observed at about 300, 360, 450, and 540 °C for 0.05, 0.08, and 0.11, respectively. It was also found that reannealing at 1150 °C for 12 h transforms these ceramics from triclinic to a metastable monoclinic phase which was found to be an irreversible process.
Comparison on the effect of and buffer layers on fatigue properties of thin films prepared by pulsed laser deposition87(2000); http://dx.doi.org/10.1063/1.373598View Description Hide Description
The fatigue properties of (PSrTO) thin filmsdeposited using (LSMO) materials as buffer layer were compared with those of the filmsgrown using (LSCO) materials as buffer layer. The extent of degradation induced by polarization switching for cycles with 210 kV/cm maximum field, which is four times of coercive field is less pronounced for PSrTO/LSMO/Pt(Si) thin films than that for PSrTO/LSCO/Pt(Si) films. This phenomenon is ascribed to the smaller strain induced in PSrTO/LSMO/Pt(Si) materials. Moreover, the pulse response testing indicates that the degradation of the films mainly occurs at PSrTO-to-LSMO (or PSrTO-to-LSCO) interface.