Preparation of Barium Titanate/Solder Composite Particles by Rotating Drum Method and PTCR Property of the Composite Particles

Abstract

We developed a new method to produce composite particles, in which soft metal particles are adhered onto the surface of core particles. The composite particles of barium titanate and solder are prepared as follows. Barium titanate particles of 200-700μm and solder particles less than 20μm are loaded into a cylindrical vessel and mixed by rotating the vessel for several hours. The solder particles are flattened out at the surface and are tightly combined with the core particles.
Effects of particle size and the rotating time on the process are investigated. The surface coverage of core particles by solder particles is decreased by reducing the core particle size. The composite particles of barium titanate and solder are packed between two electrodes in silica tube to measure the PTCR property of the cell. It is shown that the cell works as a thermistor.