No abstract

No abstract

No abstract

NiO-BaTiO 3 composites were prepared by sintering BaTiO 3 together with NiO in air at 1300°C. Microstructure and morphology of the composites were detected by XRD and SEM, and the dielectric properties were measured by LCZ meter. The results indicate that the perovskite phase is formed in fact in status of solid solution doped with Ni 2+ , although only a small amount of Ni ions can dissolve into the perovskite phase. Ni doping decreases the formation temperature of the composite without inhibiting the grain growth of the crystalline phase. The dielectric constant decreases sharply and the dielectric loss decreases smoothly with increasing Ni 2+ below NiO addition of 0.5 wt.%. When NiO addition increases above 0.5 wt.%, the dielectric constant and loss correlate with mixing rule of the two phases. Meanwhile, the replacement of Ni 2+ for Ti 4+ decreases the Curie temperature of perovskite phase by 30°C.

In recent years, Schiff base-related conjugated systems have received extensive attention, but little research has been done in the field of electromagnetic materials. In this work, an organic conjugated system based on polypyrrole/hydrazone Schiff base (PPy/HSB) composites was constructed via a Schiff base synthetic route and their electromagnetic behavior was investigated. The electromagnetic response of PPy/HSB complexes demonstrates fine electromagnetic absorption performance. When the filler loading is 30 wt% in a paraffin matrix, an absorption peak of −43.1 dB was achieved and its effective absorption bandwidth (EAB) was located in the range of 10.88−18.0 GHz. The electromagnetic response behavior of PPy/HSB complexes is explained by models involving electronic structure, multi-polarization and conductive network. The mechanisms of PPy/HSB complexes formation and HSB crystallization are also discussed through the compatibility of PPy/HSB and the structure of HSB. Moreover, the morphology transformation of HSB in the PPy/HSB systems has been studied. This study opens the exploration of organic–dielectric conjugated systems in the field of electromagnetic materials, and significantly broadens the application range of organic–dielectric–dielectric composites.