A review on piezoelectric ceramics and nanostructures: fundamentals and fabrications

The piezoelectric property was found by Curie brothers in quartz and Rachel salt (1881). This property is a complicated phenomenon that makes it challenging to study. In 1935, the piezoelectric properties of potassium-dehydrogenated phosphate, the first famous piezoelectric material, were determined. Study about these properties of materials was developed by USA, Russia, and Japan during the Second World War, resulting in some piezoelectric materials such as barium titanate (BT) and lead zirconate titanate (PZT) in 1940 and 1950, respectively. Pure and doped PZT families have been widely studied in ceramics and nanostructured forms to enhance their piezoelectric properties. Because of the lead, the PZT materials are harmful to the environment. Therefore, it has been tried to replace it with suitable lead-free materials for practical purposes. The first lead-free piezoelectric material investigated in this respect is BT. However, the piezoelectric properties of BT are not as good as PZT, so a new generation of lead-free piezoelectric materials has been developed. These new lead-free piezoelectric materials are divided into two categories: (1) the lead-free piezoelectric material based on BNT (bismuth niobium titanate) and (2) the lead-free piezoelectric material based on KNN (potassium sodium niobite). The most significant advantage of these materials is that they are environmentally friendly, but their piezoelectric properties are less than PZT. In this chapter review, lead-based and lead-free piezoelectric materials such as PZT, BT, BZT, KNN, BNT, and ZnO are studied. The synthesized methods of piezoelectric materials in ceramic and nanostructure forms are presented. The applications of piezoelectric ceramics and nanostructures are discussed.