EFFECT OF YTTRIUM DOPING ON THE FERROELECTRIC FATIGUE AND SWITCHING CHARACTERISTICS OF PB(ZR0.65TI0.35)O-3 THIN-FILMS PREPARED BY SOL-GEL PROCESSING

Variations of remanent polarization and coercive field of undoped and yttrium doped Pb(Zr0.6Ti0.35)O-3 thin films prepared by Sol-Gel proces sing were observed using hysteresis measurement according to the cumul ative switching cycles. Remanent polarization and coercive field of un doped Pb(Zr0.65Ti0.35)O-3 thin films after 10(10) polarization reversa ls were decreased and increased, respectively. But the variations of r emanent polarization and coercive field of yttrium doped specimens wit h the polarization switching cycles were different from those of undop ed specimens. In the case of yttrium doped specimens, remanent polariz ations were not decreased and coercive fields were increased more than those of undoped specimens after fatigue. It was well known that dope d yttrium reduced holes and increased vacancies in PZT thin films. Thi s strongly suggests that the variations of holes and vacancies influen ce on the remanent polarizations and the coercive fields of Pb(Zr0.65T i0.35)O-3 thin films after fatigue. Also, switching time was reduced a s the yttrium doping increased.