ZnAl2O4–TiO2–SrAl2Si2O8 low-permittivity microwave dielectric ceramics

(1−x)(0.75ZnAl2O4–0.25TiO2)–xSrAl2Si2O8 (abbreviated as (1−x)ZAT–xSAS) 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–xSAS ceramics to near-zero value. In addition, ZnAl2O4 spinel, TiO2 rutile and SrAl2Si2O8 monoclinic phases can coexist in the (1−x)ZAT–xSAS system, which is helpful to control the microwave dielectric properties and obtain a serial εr value from 3.56 to 12.20 by changing the phase composition. Therefore, (1−x)ZAT–xSAS could be a kind of zero-shrinkage and low-permittivity microwave dielectric ceramics for many potential applications in the future.