DIN IEC/TS 61994-4-2:2012-05

This part of IEC 61994 specifies terms and definitions for piezoelectric and dielectric materials - piezoelectric ceramics - which are used for piezoelectric and electrostatic devices representing the present state-of-the-art. The dictionary explains terms such as: - piezoelectric ceramics, ceramics with a high dielectric constant which are given piezoelectricity by polarizing property; - piezoelectric effect, the ability to generate an electric potential in response to applied mechanical stress; - coupling coefficient (electro-mechanical coupling coefficient) is a constant representing the piezoelectric efficiency of a piezoelectric ceramic, the efficiency of converting electrical energy into mechanical energy; - expansion vibration, vibration mode of a disc or plate where the displacement is in the plane surface; - flexural vibration, for a resonator shaped as a thin narrow bar, displacements appearing in a direction perpendicular to the length of the bar; - trapped vibration mode, the vibration mode the wave energy of which is trapped in the electrode region on the piezoelectric ceramic resonator shaped as a thin plate and vibrating in a thickness mode. These terms are intended for use in the standards and documents of Technical Committee IEC/TC 49. The responsible committee is K 642 "Piezoelektrische Bauteile zur Frequenzstabilisierung und -selektion" ("Piezoelectric and dielectric devices for frequency control and selection") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.