INFLUENCE OF TEXTURE ON THE SWITCHING BEHAVIOR OF PB(ZR0.70TI0.30)O-3SOL-GEL DERIVED THIN-FILMS

Citation
Kg. Brooks et al., INFLUENCE OF TEXTURE ON THE SWITCHING BEHAVIOR OF PB(ZR0.70TI0.30)O-3SOL-GEL DERIVED THIN-FILMS, Journal of materials research, 12(2), 1997, pp. 531-540
Citations number
30
Categorie Soggetti
Material Science
ISSN journal
08842914
Volume
12
Issue
2
Year of publication
1997
Pages
531 - 540
Database
ISI
SICI code
0884-2914(1997)12:2<531:IOTOTS>2.0.ZU;2-M
Abstract
Rhombohedral Pb(Zr0.70Ti0.30)O-3 thin films of four different well-def ined textures, namely, (100), (111), bimodal (110)/(111), and (100)/(1 11), were prepared by a sol-gel method. The films were characterized i n terms of grain size, presence of second phases, surface roughness, c olumnarity of grains, and other microstructural features. The dielectr ic, ferroelectric, and fatigue properties were investigated, with emph asis on the hysteresis switching characteristics. Results are discusse d from the reference point of the allowable spontaneous polarization d irections available for the different textures. The values of coercive held, remanent and saturation polarization, and slope of the loop at the coercive held, at saturating fields can be qualitatively explained based on the texture, independent of microstructural differences. The occurrence of surface pyrochlore, however, is observed to affect the functionality of the saturation curves, particularly for the samples o f bimodal texture. Shearing of the hysteresis curves of the bimodal fi lms is also attributed to surface microstructural features. The occurr ence of nonswitching 71 degrees or 109 degrees domains in the (111) an d (110)/(111) textured films is hypothesized based on a comparison wit h the data from the (100) textured film. Corrected saturation polariza tion values agree with the spontaneous polarization values of rhombohe dral PZT single crystals and published calculated Values for rhombohed ral PZT ceramics. The fatigue characteristics show increases in the sw itching component of polarization in the range 10(3)-10(7) bipolar cyc les, particularly for the (111) textured sample. Onset of fatigue is o bserved for all samples between 10(7) and 10(8) switching cycles.