It has become common knowledge that there are materials with a permanent magnetic moment. The fact that there is a similar phenomenon for the electric moment as well is part of the curriculum of physical or related university education, but is usually regarded as only one of many exotic effects. Primarily this is caused by the fact that the number of applications of ferroelectric materials was limited and not of general interest. Until recently ferroelectrics have mainly been used for sonar detectors, ceramic capacitors, and phonograph pick-ups, but today there is a wide interest in taking advantage of their properties in the semiconductor industry, and the first products are already entering the market.
Ferroelectricity was discovered in 1920. The first known ferroelectric material was Rochelle salt. Unfortunately, Rochelle salt loses its ferroelectric properties if the composition is slightly changed, which made it rather unattractive for industrial applications. It was mainly regarded as an interesting physical effect. In 1945, ferroelectric behavior was reported for [LG96]. This material is of stable perovskite type, which is one of the fundamental crystal lattice structures. This discovery brought the perovskite type materials into the scope of investigations. Soon other perovskites with ferroelectric properties were discovered, thus opening the path to industrial application. Perovskites are still the most important ferroelectric materials.