Ferrite ceramic filled poly-dimethylsiloxane composite with enhanced magnetic-dielectric properties as substrate material for flexible electronics

Improving magnetic-dielectric properties of polymer materials, through filler of functional ceramics, provides feasibility to develop high-frequency flexible electronics. Poly-dimethylsiloxane (PDMS), an inert silicone with low elasticity modulus and high transparency, has been considered a promising candidate for flexible electronics. Current PDMS matrix used in high-frequency devices suffers from unsatisfactory properties due to very low dielectric constant. In this study, using ultrasonic stirring and vacuum-pumping process, we prepare a series of xCo2Z/PDMS (x = 2; 4; 6; 8; 10) composite films, which are consisted of PDMS matrix and different quantity of micro-sized ferrite particles. XRD pattern indicates that the obtained ferrite particles include Co2Z main phase and BaM second phase. We demonstrate that 4Co2Z/PDMS film has improved magnetic-dielectric properties at 800 MHz (mu' = 1.49; epsilon' = 4.54 tan delta mu = 0.058; tan delta epsilon = 0.008). Also, the film has high saturation magnetization (sigma s = 17.51 emu/g). Furthermore, SEM micrographs show that using ultrasonic stirring and fast curing, the microsized ferrite particles are well dispersed in PDMS matrix. Our study, which provides a simple method to improve high-frequency magnetic and dielectric properties of PDMS matrix, could pave the way for development of highfrequency flexible electronics.