Interface-Induced Modifications in the Ferroelectric properties of 200 MeV Ag⁺¹⁵ Ion-Irradiated ZnO-BaTiO₃ Nanocomposite Films

Studies on nanocomposite films with an optimized composition of 0.6ZnO-0.4BaTiO₃/Al₂O₃ were carried out to understand the effect of swift heavy ion (SHI)-induced modifications on the ferroelectric properties inspired by interface mixing. XRD measurements showed the presence of ZnO and BaTiO₃ phases in pristine film which was modified by irradiation. Surface modifications induced by SHI irradiation, as studied using AFM, revealed the evolution of nanosized rod and hillock-like microstructure on the film surface with the increase in irradiation dose. The variations in film thickness and elemental compositions were studied using RBS spectrometry, and an intermixing zone ~ 25 nm was identified in the film irradiated by 5 × 10¹⁰ ions/cm² which increased with the ion fluence. Ferroelectric (P-E) loops showed a significant change in the hysteresis characteristics which was understood on the basis of modifications in the surface morphology and the interface between the wurtzite-structured ZnO and the perovskite-structured BaTiO₃ responsible for the space charge region.