Discover the latest advances in ferroelectric and piezoelectric material sciences with this comprehensive monograph, divided into six chapters, each offering unique insights into the field. Chapter 1 delves into the manufacture and study of new ceramic materials, focusing on complex oxides of various metals (Aurivillius phases). The authors explore layered bismuth titanates and niobates, known for their high Curie temperature, and discuss how varying their chemical composition can lead to significant changes in their electrophysical properties. Chapter 2 explores the fascinating world of ferroelectrics - dielectrics with spontaneous polarization. Mathematical models and approaches of fractional calculus are used to understand the process of polarization switching in these materials, shedding light on the fractality of electrical responses. In Chapter 3, readers gain valuable insights into the inhomogeneous polarization process of polycrystalline ferroelectrics, a crucial stage in creating piezoceramic samples for energy converters. The authors present a comprehensive mathematical model that allows the determination of various characteristics, including dielectric and piezoelectric hysteresis loops and the effect of attenuation processes. Chapter 4 focuses on state-of-the-art piezoelectric energy harvesting, discussing theoretical, experimental, and computer modelling approaches. The authors discuss piezoelectric generators (PEGs) of different types (cantilever, stack and axis) and nonlinear effects arising at their operation. Chapter 5 presents expanded test and finite element models for cantilever-type and axial-type PEGs with active elements. The studies cover various structural and electric schemes of the PEGs with proof mass, bimorph and cylindrical piezoelectric elements, and excitation loads. Finally, Chapter 6 reviews some results in the last five years, obtained in modelling the vibration of devices from piezoactive materials, including five important effects: piezoelectric, flexoelectric, pyroelectric, piezomagnetic and flexomagnetic. As a diverse addition to the literature, this book is a relevant resource for researchers, engineers, and students seeking to expand their knowledge of cutting-edge developments in this exciting field.