  Developing novel lead-free ferroelectric materials is crucial for
next-generation microelectronic technologies that are energy efficient and
environment friendly. However, materials discovery and property optimization
are typically time-consuming due to the limited throughput of traditional
synthesis methods. In this work, we use a high-throughput combinatorial
synthesis approach to fabricate lead-free ferroelectric superlattices and solid
solutions of (Ba0.7Ca0.3)TiO3 (BCT) and Ba(Zr0.2Ti0.8)O3 (BZT) phases with
continuous variation of composition and layer thickness. High-resolution X-ray
diffraction (XRD) and analytical scanning transmission electron microscopy
(STEM) demonstrate high film quality and well-controlled compositional
gradients. Ferroelectric and dielectric property measurements identify the
optimal property point achieved at the morphotropic phase boundary (MPB) with a
composition of 48BZT-52BCT. Displacement vector maps reveal that ferroelectric
domain sizes are tunable by varying {BCT-BZT}N superlattice geometry. This
high-throughput synthesis approach can be applied to many other material
systems to expedite new materials discovery and properties optimization,
allowing for the exploration of a large area of phase space within a single
growth.
