A classroom experiment to demonstrate ferroelectric hysteresis

We have developed a classroom experiment suitable for undergraduate students in which they fabricate a ferroelectric capacitor from potassium nitrate and then observe the electrical behavior as the film is cooled through its transition temperature. The experiment can be carried out using a capacitance bridge that is simple to construct and inexpensive. The experiment gives students a hands-on experience with ferroelectric phenomena, a subject of considerable interest from both a fundamental and a technological standpoint.