Ferroelectrics of Ultrafine Particle Size: III, Thin Barium Titanate Layers for Capacitors

The large change in the dielectric constant of barium titanate near 120°C was smoothed out by the use of very small particle sizes and additions of tantalum oxide. Unsupported thin sheets of the material showed the same electrical properties as thick pellets. Stacked capacitors made from these sheets, using platinum electrodes, showed a maximum capacitance change over the range 25° to 180°C of 19 to 27%, based on the room-temperature value.