title: Process and Microstructure to Achieve Ultra-high Dielectric Constant in Ceramic-Polymer Composites.
abstract: Influences of process conditions on microstructure and dielectric properties of ceramic-polymer composites are systematically studied using CaCu3Ti4O12(CCTO) as filler and P(VDF-TrFE) 55/45 mol.% copolymer as the matrix by combining solution-cast and hot-pressing processes. It is found that the dielectric constant of the composites can be significantly enhanced-up to about 10 times - by using proper processing conditions. The dielectric constant of the composites can reach more than 1,000 over a wide temperature range with a low loss (tan δ ~ 10-1). It is concluded that besides the dense structure of composites, the uniform distribution of the CCTO particles in the matrix plays a key role on the dielectric enhancement. Due to the influence of the CCTO on the microstructure of the polymer matrix, the composites exhibit a weaker temperature dependence of the dielectric constant than the polymer matrix. Based on the results, it is also found that the loss of the composites at low temperatures, including room temperature, is determined by the real dielectric relaxation processes including the relaxation process induced by the mixing.
authors: Materials Research and Education Center, Auburn University, Auburn, AL 36849, USA.
authors: Lin
authors: L
authors: Zhang
authors: Materials Research and Education Center, Auburn University, Auburn, AL 36849, USA.
authors: Xiaobing
authors: X
authors: Shan
authors: Materials Research and Education Center, Auburn University, Auburn, AL 36849, USA.
authors: Patrick
authors: P
authors: Bass
authors: Materials Research and Education Center, Auburn University, Auburn, AL 36849, USA.
authors: Yang
authors: Y
authors: Tong
authors: Marshall Space Flight Center, Huntsville, AL 35812, USA.
authors: Terry D
authors: TD
authors: Rolin
authors: Marshall Space Flight Center, Huntsville, AL 35812, USA.
authors: Curtis W
authors: CW
authors: Hill
authors: Marshall Space Flight Center, Huntsville, AL 35812, USA.
authors: Jeffrey C
authors: JC
authors: Brewer
authors: Marshall Space Flight Center, Huntsville, AL 35812, USA.
authors: Dennis S
authors: DS
authors: Tucker
authors: Materials Research and Education Center, Auburn University, Auburn, AL 36849, USA.
authors: Z-Y
authors: ZY
authors: Cheng