Annealing induced effect on the physical properties of ion-beam sputtered 0.5 Ba(Zr0.2Ti0.8)O3 – 0.5 (Ba0.7Ca0.3)TiO3-δ ferroelectric thin films.

This work reports thermal annealing induced effect on the structural, optical, chemical and ferroelectric properties of ion-beam sputtered lead-free ferroelectric 0.5 Ba(Zr 0.2 Ti 0.8 )O 3 – 0.5 (Ba 0.7 Ca 0.3 )TiO 3-δ (0.5BZT–0.5BCT) thin films. X-ray diffraction studies reveal that the tetragonality increases with the annealing temperature (T a ), while photoluminescence and X-ray photoelectron spectroscopy studies confirm that this effect is associated with the annihilation of the oxygen vacancies as well as changes in the Ba 2+ coordination. The films annealed at 750 °C show a remarkable remnant polarization of P r  = 45.0 μC/cm 2 , with a coercive field of 32 kV/cm. The temperature dependence of the spontaneous polarization of the 0.5BZT–0.5BCT film reveals a mean field behavior of the polarization and the fatigue study reveals that P r only decreases 3% after passing 10 9 cycles. Therefore the high remnant polarization and its high P r stability make these films as promising candidates for memory applications. [ABSTRACT FROM AUTHOR]