High-Throughput Combinatorial Approach to The Synthesis of a Lead-Free Relaxor Ferroelectrics System

Developing novel lead-free nontoxic ferroelectric materials is crucial for the next-generation microelectronic technologies in regard to clean energy and environmental sustainability. However, materials discovery and properties optimization have usually been a frustratingly slow process due to the limited throughput in traditional synthesis methods. In this work, using a high-throughput combinatorial synthesis approach, we fabricated lead-free ferroelectric superlattices and solid solutions of (Ba_0.7Ca_0.3)TiO₃ (BCT) and Ba(Zr_0.2Ti_0.8)O₃ (BZT) phases with compositional gradients. The high-resolution X-ray diffraction and scanning transmission electron microscopy (STEM) revealed the good film quality and well-controlled compositional gradient throughout the samples. Ferroelectric and dielectric properties identified the “optimal property point” achieved at the morphotropic phase boundary (MPB) with the composition of BZT-52BCT. The displacement vector maps revealed the tunable ferroelectric domain sizes by varying the single layer thickness of the {BCT/BZT}_n superlattices. This high-throughput synthesis approach can be applied to many other materials systems to expedite novel materials discovery and property investigations.