Multiple structural components and their competition in the intermediate state of antiferroelectric Pb ( Zr , Ti ) O 3

Antiferroelectric perovskites form an important family of functional electric materials, which have high potential in energy storage and conversion applications. However, a full understanding of their crystal structural formation is still lacking. ${\mathrm{PbZrO}}_{3}$-based materials can serve as a model system for investigation, not only because ${\mathrm{PbZrO}}_{3}$ was the first discovered antiferroelectric, but also because it undergoes a typical phase transition sequence from a high-temperature paraelectric to the low-temperature antiferroelectric phase, passing through a possible intermediate phase that is poorly understood. Here we employ a combination of optical and scattering experiments and theoretical calculations to reveal the nature of the intermediate state. Evidence is found that this peculiar state consists of multiple short-range and long-range structural components, and their competition is crucial in stabilizing the antiferroelectric phase. External stimuli such as temperature change or chemical substitution can easily alter each component's energy landscape and thereby change the materials' electrical properties. These findings provide insights into understanding antiferroelectric-ferroelectric competition and can be useful in designing alternative antiferroelectric materials.