ELECTRICAL CHARACTERISATION OF FERROELECTRIC CERAMICS

Abstract

Ferroelectric ceramics were born in the early 1940’s with the discovery of the phenomenon of ferroelectricity as the source of the unusually high dielectric constant in ceramics. Since that time, they have been the heart and soul of several multi-billion-dollar industries, ranging from high dielectric constant capacitors to later developments of piezoelectric transducers, PTC devices and electro-optic light valves. The era of ferroelectricity began in early 1940’s under a cloud of secrecy, because World War 2 was under way. Materials based on two compositional systems, barium titanate and lead zirconate titanate, have dominated the field throughout their history. The more recent developments in the field of ferroelectric ceramics, such as medical ultrasonic composites, high-displacement piezoelectric actuators (Moonies, RAINBOWS), photostrictors, and thin and thick films for piezoelectric and integrated-circuit applications have served to keep the industry young amidst its growing maturity.