Donor-acceptor co-doped Ba0.675Sr0.325TiO3 filled Poly(vinylidene fluoride) demonstrating significantly enhanced tunability for tunable device applications

Ferroelectric materials with high dielectric tunability are widely investigated to meet the demands of microwave device. Ion doping has proven to be an effective method to enhance the dielectric tunability of ferroelectric ceramics . However, high-temperature processing, rigidity , and high density are the obstacles associated with these ceramic materials which limits their application. In this study, Cr 3+ and La 3+ co-doped Ba 0.675 Sr 0.325 TiO 3 ceramic (BSTLC) is used as filler particles in poly (vinylidene fluoride) (PVDF) matrix to produce flexible composite material. With addition of 12 vol% BSTLC, the dielectric constant ( D k ) of the PVDF composites is 16.7, which is higher by 85.6 % and 10.1 % compared to pure PVDF and undoped-BST/PVDF composite, respectively. Meanwhile, a high dielectric tunability of 9.1 % is achieved, which shows an increase of 105 % compared to the BST/PVDF composite (4.4 %). The co-doping of Cr 3+ and La 3+ in the BST filler provides an effective strategy for adjusting the dielectric tunability properties of polymer-based composites.