Dielectric Enhancement and Maxwell-Wagner Effect in Polycrystalline BaTiO₃/Ba_0.2Sr_0.8TiO₃ Multilayered Thin Films

Polycrystalline BaTiO₃/Ba_0.2Sr_0.8TiO₃ multilayer thin films were fabricated by pulsed-laser deposition onto Pt/Ti/SiO₂/Si substrates with various stacking periodicities. The dielectric constant of the films was obviously enhanced with decrease of the individual layer thickness, while the dielectric loss was kept at a low level comparable to that of the pure Ba_0.6Sr_0.4TiO₃ thin films. The Maxwell-Wagner model is used to explain the experimental data.