Kecheng Li

Surface functionalized Ba0.6Sr0.4TiO3 /poly(vinylidene fluoride) nanocomposites with significantly enhanced dielectric properties

A nanocomposite was prepared by embedding Ba0.6Sr0.4TiO3 (BST)/silver core/shell nanoparticles (BST@Ag) into polyvinylidene-fluoride (PVDF). Through functionalizing the surface of BST nanoparticles by silver coating, the relative permittivity of composites was significantly increased to 153 at 100 Hz which is 73% higher than that of the composite making of untreated BST nanoparticals. The loss tangent was still low (less than 0.2) when the filler content of BST@Ag was 0.55. Increasing the conductivity of the interlayer between BST and PVDF by silver enhances the space charge polarization and forms a nanocapacitance network through the interparticle junctions connecting the electrodes of sample.

Effect of B2O3 Additions on the Sintering Temperature and Microwave Dielectric Properties of 5.5Li2O-Nb2O5 −7TiO2 Ceramics

The effects of B 2 O 3 addition on the sintering behavior, microstructure, and the microwave dielectric properties of 5.5Li 2 O-Nb 2 O 5− 7TiO 2 (LNT) ceramics have been investigated. The low-amount addition of B 2 O 3 can effectively lower the sintering temperature of LNT ceramics from 1075 to 875°C and induce no obvious degradation of the microwave dielectric properties. Typically, the 1.0 wt.% B 2 O 3 added ceramic sintered at 875°C has better microwave dielectric properties of ϵ r = 40.8, Q × f = 15, 560 GHz, τ f = 50 ppm/°C. Obviously, the LNT ceramics can be applied to microwave LTCC devices.