A study of characterization and applications of piezoelectric ceramics materials

Piezoelectricity is the ability of certain crystalline materials to develop an electric charge proportional to a mechanical stress, which is called the direct piezoelectric effect discovered by Curie bothers in 1880. Soon it was realized that materials showing this phenomenon must also show the converse piezoelectric effect: a geometric strain/deformation proportional to an applied voltage. Typical crystals (e.g., quartz, tourmaline and Rochelle salt) exhibit the piezoelectric effect. Since its discovery the piezoelectricity effect has found many useful applications, such as the production and detection of sound, generation of high voltages and frequency, microbalances, and ultra-fine focusing of optical assemblies. It is also the basis of a number of scientific instrumental techniques with atomic resolution such as the scanning probe microscopy, and everyday uses such as acting as the ignition source for cigarette lighters and pushstart propane barbecues. However, the traditional piezoelectric single crystals suffer from the disadvantages such as weak piezoelectric effect, low mechanical strength, sensitivity to moisture, and very narrow operated temperature range. Compared to the traditional single crystals, electrically poled polycrystalline ferroelectric ceramics, such as barium titanate (BaTiO3) and lead zirconium titanate (PZT), offer the advantages of large and stable piezoelectric effects, high strength and ease of fabrication in general, especially into complex shapes and large area pieces. Nowadays, they become the dominant piezoelectric materials in the fields of piezoelectric applications such as actuators, sensors, and transducers in intelligent systems and smart structures, dominating the world market today.