Microstructure and optical property in an irregular multilayer comprising ferroelectric and paraelectric materials

A special sequence of multilayer, consisting of PbZr_0.5Ti _0.5O₃ and SrTiO₃ films, was fabricated using a simple chemical solution deposition. X-ray diffractometer (XRD) measurement reveals that each film in this multilayer has been crystallized into the single perovskite phase. The high-angle annular dark-field scanning transmission electron microscopy (STEM) image shows that the obtained SrTiO ₃/PbZr_0.5Ti_0.5O₃ multilayer contains three components with different optical thicknesses: dense and porous PbZr _0.5Ti_0.5O₃ layers, together with dense SrTiO₃ layers. This multilayer system exhibits superior optical performance, with a peak reflectivity of∼95% and a bandwidth of ∼113 nm, rendering its promising candidate as dielectric mirrors, optical cavities, and selective filters.