Fabrication Process And Microwave Dielectric Property Research Of Tungstate Ceramics

Microwave dielectric ceramics have been widely investigated in recent years due to their applications in high-tech fields.Low Temperature Co-fired Ceramic(LTCC)has gained extensive attention for its excellent dielectric properties,which also make AWO4,a typical LTCC,particularly valuable.In this study,tungstate microwave dielectric ceramics was prepared by solid-state reaction process.Then the structural characters and dielectric properties of the samples were given preliminarily.Moreover,the crystal structure of tungstate compound was successfully calculated using Materials Studio,a calculation software,A consistent result was received by comparing the calculated XRD pattern with the experimental measured pattern,which lays a good foundation for further theory study.(1)AWO4(A=Zn,Mg,Co,Ni)microwave dielectric ceramics were successfully prepared based on the designed processing conditions,their phase compositions,microstructures and microwave dielectric properties were also analyzed.Effects of different sintering temperature on density and dielectric properties of AWO4 microwave dielectric ceramics was analyzed,XRD test result is correspond with the exclusive diffraction peak of standard card ICDD-PDF#88-0251.Volume density,dielectric constant and quality factor of AWO4 microwave dielectric ceramics lifted as sintering temperature increased.Among the four AWO4 microwave dielectric ceramics,ZnWO4 holds better performance,whose density can reach to 6.981g/cm3 under sintering temperature of 1150 oC.Its microwave dielectric properties was listed as below:(28)33.15r?,Q×?=38300GHz,-(28)1.14f?ppm/?;(2)Four different mass proportion of CuO were added to reduce the sintering temperature and improve their density,The results of XRD test agreed with standard card ICDD-PDF#88-0251,with no second phase generating.The results of microwave dielectric properties test showed that density and dielectric constant ascended while sintering temperature increased,while quality factor dropped to some extent.More obvious increasement of density and dielectic constant were observed with higher CuO proportion,the microwave dielectric properties of ZnWO4-1wt%CuO ceramic samples under sintering temperature of 1100 oC were listed as below:(28)10.15r?,Q×?=4398GHz,-(28)5.11f?ppm/?;(3)Structure of AWO4(A=Zn,Mg,Co,Ni)is identical to monoclinic phase wolframine.Theoretical calculation pattern of AWO4 structure was obtained by using MS software,the pattern is tally with the pattern obtained from ceramic sample tests,which paves a way for further theory study.