Relaxor/Ferroelectric Composites: A Solution in the Quest for Practically Viable Lead-Free Incipient Piezoceramics

Abstract

Recently developed lead-free incipient piezoceramics are promising candidates for off-resonance actuator applications with their exceptionally large electromechanical strains. Their commercialization currently faces two major challenges: high electric field required for activating the large strains and large strain hysteresis. It is demonstrated that design of a relaxor/ferroelectric composite provides a highly effective way to resolve both challenges. Experimental results in conjunction with numerical simulations provide key parameters for the development of viable incipient piezoceramics. Incipient piezoceramics are featured by giant strain of ≈0.4%. However, this giant strain is only realized at relatively large electric field (>4 KV mm-1) with a significant strain hysteresis. Here, many of the challenges the incipient piezoceramics face can be overcome by relaxor/ferroelectric composite approach.