The permittivity of hydrostatically stressed dielectrics

Abstract
Experiments have been carried out to determine the change of permittivity of some well-known solid dielectrics with pressure. The dielectrics, in the form of slabs of the order of 0.1 mm thick and 1 cm2 in area, were submitted to hydrostatic pressures up to 3000 kg/cm2 in oil, and the fractional change in capacity was observed. Dielectrics investigated included alkali halides, polystyrene, polyethylene, rutile and ammonium iodide.