ZnAl2O4–TiO2–SrAl2Si2O8 low-permittivity microwave dielectric ceramics

Abstract (1− x )(0.75ZnAl 2 O 4 –0.25TiO 2 )– x SrAl 2 Si 2 O 8 (abbreviated as (1− x )ZAT– x SAS) ceramics were prepared by the solid-state reaction. The effects of SAS content on shrinkage, phase compositions, microstructure and microwave dielectric properties were investigated. It shows that SAS with a rare negative shrinkage characteristic can effectively adjust the shrinkage of the (1− x )ZAT– x SAS ceramics to near-zero value. In addition, ZnAl 2 O 4 spinel, TiO 2 rutile and SrAl 2 Si 2 O 8 monoclinic phases can coexist in the (1− x )ZAT– x SAS system, which is helpful to control the microwave dielectric properties and obtain a serial e r value from 3.56 to 12.20 by changing the phase composition. Therefore, (1− x )ZAT– x SAS could be a kind of zero-shrinkage and low-permittivity microwave dielectric ceramics for many potential applications in the future.