Calcium copper titanate (CaCu₃Ti₄O₁₂, CCTO) particles with three types of particle size (CCTO–i, CCTO–ii, CCTO–iii) are prepared by wet chemical method. And then the dielectric composites based on CCTO particles and Phenol formaldehyde resin (PF) are fabricated by mixing and mould pressing. This paper mainly studies the microstructure and dielectric properties of CCTO/PF dielectric composites (CCTO–i, CCTO–ii and CCTO–iii composites). XRD, FTIR and SEM indicate that the CCTO particles are dispersed in the polymer matrix. In addition, the effect of particle size on the dielectric properties of CCTO/PF composites is also discussed. By comparing the CCTO/PF composites with different particle sizes, it is found that the CCTO–i composite has a high maximum dielectric constant and low loss at room temperature of 100 Hz, while the CCTO volume fraction was 0.5 in the measurement frequency range, which shows a very weak frequency dependence. On this basis, the CCTO–i composite with relatively small particle size has excellent dielectric properties, which may imply that the effect of interface will be changed by smaller particle size.

Keywords: CCTO particles, PF, Particle size, Dielectric property