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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(Zr0.2Ti0.8)O3 – 0.5 (Ba0.7Ca0.3)TiO3-δ (0.5BZT–0.5BCT) thin films. X-ray diffraction studies reveal that the tetragonality increases with the annealing temperature (Ta), 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 Ba2+ coordination. The films annealed at 750 °C show a remarkable remnant polarization of Pr = 45.0 μC/cm2, 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 Pr only decreases 3% after passing 109 cycles. Therefore the high remnant polarization and its high Pr stability make these films as promising candidates for memory applications, Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding Contract UID/FIS/04650/2013; (ii) Project Norte-070124-FEDER-000070 Nanomateriais Multifuncionais. The author J.P.B.S. is grateful for financial support through the FCT Grant SFRH/BPD/92896/2013. The authors acknowledge the CERIC-ERIC Consortium for access to experimental facilities and financial support under proposal CERIC-ERIC-20167010. The author K.C. Sekhar acknowledge UGC and DST-SERB, Govt. of India for the funds through the grant no. F.4-5(59-FRP/2014(BSR)) and ECR/2017/000068, info:eu-repo/semantics/publishedVersion

In this work, resistive switching in pulsed laser deposited ferroelectric lead-free 0.5Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 (0.5BZT–0.5BCT) thin films was investigated. This study reveals that films grown at 5.5 J cm−2 have shown optimal ferroelectric and resistive switching response, which are attributed to high tetragonality, large grain size and less defect concentration. Au/0.5BZT–0.5BCT/Pt capacitors show the electroforming free resistive switching that is explained based on the polarization modulation of the Schottky-like barrier at the 0.5BZT–0.5BCT/Au interface. The polarization induced resistive switching is evidenced by its disappearance as the temperature increases to the Curie temperature. The capacitor based on film grown at 5.5 J cm−2 shows resistive switching characterized by high switching ratio of 106 at a low set/reset voltage ≈1V, and by a stable memory window, which are highly required for memory applications., This study has been partially funded by: (i) Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013; (ii) Project Norte- 070124-FEDER-000070 Nanomateriais Multifuncionais. The author JPBS is grateful for financial support through the FCT Grant SFRH/BPD/92896/2013. The authors would like to acknowledge the contribution of the COST Action MP1308- TO-BE. The authors would also like to thank Engineer José Santos for technical support at Thin Films Laboratory.