Development of potassium bismuth titanate based lead-free materials for piezoelectric applications

Abstract

In modern development, electronic products demand high performance, flexibility, multifunctionality, self-powering, lightweight, and miniaturization. Functional materials such as triboelectric, pyroelectric, piezoelectric, and ferroelectric demonstrated great potential to satisfy the underlying requirements of today's commercial market [1, 2]. These materials can be employed in a diverse range of applications, from small-scale products (sensors, actuators, transducers) to large systems (vibration dampeners, energy generators, etc.). The discovery of functional materials began in the early 19th century (in 1824) when David Brewster observed the electric charge generation in Rochelle salt on changing its temperature. This behavior was called "pyroelectricity", where the Greek word pyr refers to fire or heat [3]. The piezoelectric effect was first noticed in a quartz crystal by Pierre and Jacques Curie in 1880, where electric charges were produced in response to mechanical stress or pressure. This effect was named as direct piezoelectric effect. The term "piezoelectricity" is derived from the combination of the Greek word piezo (pressure) and electricity (motion of charges). Later, in 1881, Gabriel Lippmann observed the change in the material's dimensions under an external electric field and named it the converse piezoelectric effect [4]. Further, Joseph Valasek discovered ferroelectricity in 1921 while working on Rochelle salt [5].