High-Throughput Combinatorial Approach to the Synthesis of a Lead-Free Ferroelectric Relaxor System

Materials discovery and optimization have usually been a frastrating slow process due to the limited materials combination options in traditional sysnthesis methods. Here, a high-throughput combinatorial approach which can fabricate nanocomposite materials with compositional gradients at nanoscale has been demonstrated. In this work, the lead-free (BCT-BZT) nanocomposite system was chosen owing to their large piezoelectric coefficient, high dielectric permittivity and robust thermal stability, making it a promising candidate to replace Pb-based energy storage devices. A series on BCT-BZT superlattice structures with continuous compositional gradient were fabricated through a combinatorial pulsed laser technique (cPLD). Ferroelectric property measurements demonstrate the tunable ferroelectricity and relaxor behaviors at different locations on the specimens by changing the BCT: BZT composition ratio as well as the alternating layersnumber and thicknesses. Detailed microstructural characterization including high resolution X-ray, transmission electron microscopy, and spectroscopy analyses were conducted to clarify the superlattaice epitaxy quality, interface structural coupling, and the structure-property correlation of the {xBCT/(1-x)BZT} superlattice films. The high-throughput synthesis approach demonstrate in this work can be applied to various materials systems to expedite the synthesis and property optimization processes of novel materials systems.