Microwave Dielectric Ceramics Ytinbo <sub> Preparation And Properties Of 6 </ Sub>,

To meet the requirement of communication technology,such as cellular telephone,Global positioning,microwave ceramics,which are mainly used in resonators,Should have high dielectric constantsε_r that enable the miniaturization of devices,high Q_f factors that transport,filter or store electromagnetic energy,and low coefficient of thermal variation of resonant frequency(Ï„_f)to avoid influence of environment or circuit heating.The niobate microwave dielectric ceramics YTiNbO₆ were used as studied object.The sintered samples were prepared by conventional solid-state ceramic route.Their microstructures were analyzed using XRD,SEM and EDS and the Microwave dielectric properties of YTiNbO₆ were investigated using network analyzer(Agilent8719ET)in this paper.Firstly,the YTiNbO₆ ceramics were prepared by the conventional solid-state ceramics route.the effect of sintering parameter,calcination and sintering temperature and soaking time on microstructures and microwave dielectric properties were investigated Secondly,the effect of MnO₂ and ZnO on microstructures and microwave dielectric properties of YTiNbO₆ were investigated.The main results of the sets of experiments are list as follows:(1)The YTiNbO₆ ceramics with good microwave dielectric properties were prepared by the conventional solid-state ceramics route.Good microwave dielectric properties ofε_r=20.2,Q_f=19548 GHz andÏ„_f=-58.39 ppm/℃could be obtained in YTiNbO₆ ceramics when calcined at 1150℃and sintered at 1380℃for 4h.(2)The microwave dielectric properties were improved for few addition of ZnO.Good microwave dielectric properties ofε_r=20.67,Q_f=29253GHz andÏ„_f =-56.66ppm/℃could be obtained in YTiNbO₆ ceramics doped with 1Wt%ZnO.(3)The microwave dielectric properties were improved for few addition of MnO₂.Good microwave dielectric properties ofε_r=21.15,Q_f=25048 GHz andÏ„_f=-51.19 ppm/℃could be obtained in YTiNbO₆ ceramics doped with 0.5Wt% MnO₂.(4)The doping of MnO₂ and ZnO reduced the sintering temperature as the sintering additives.The sintering temperatue of YTiNbO₆ ceramics doped with MnO₂ and ZnO decreased from 1380℃to 1340℃.