Formation And Transformation Of ZnO-TiO₂ System Microwave Dielectric Ceramics By Sol-gel Process

As ZnTiO3 has the outstanding dielectric property and low sintering temperature, it has been mixed with Ag,Cu,etc. to prepare electrodes at relatively low sintering temperature. In the light of the fact that the hexagonal close packing ZnTiO3 is easily decomposed to Zn2TiO4 and TiO2 of bad dielectric property above 945℃, it affects ZnTiO3 microwave dielectric property. And based on the development and requirement of miniaturization,high frequency vulcanization and low cost of instrument ,the investigator needs improving technology to get dielectric ceramics of better dielectric property .So,in this thesis sol-gel process was adopted and C16H36O4Ti,inorganic salt Zn(NO3)2·6H2O (instead of organic salt) were used at low cost as precursor,CH3CH2OH as solvent,acetic acid glacial used to adjust pH. According to triple orthogonal test :we find that the solution PH is about 2.3 to 2.5, the mole rate of C16H36O4Ti and acetic acid glacial is 4, the mole rate of C16H36O4Ti and CH3CH2OH is 7:1, is the best formula situation in the experiments. And the best Ti/Zn=1:1, the best sintering temperature of ilmennite ZnTiO3 powder is 800℃.Doping different content V2O5 we adopted semichemical method to prepare ZnTiO3 powder and discussed ZnTiO3 dielectric property. The results is as follows: doping V2O5 make the decomposition temperature of ZnTiO3 below 850℃.when sintering in 920℃for 4 hours, doping 0.7wt% V2O5 toZnO-TiO2 ceramics ,its density can reach 92% of theoretical density; its dielectric property tested in 10GHz is as follows: Qf≈23800GHz,εr≈24.6.By dopping appropriate amount of Mg2+,Ni2+ to ilmenite ZnTiO3 , it can improve thermal stability of ZnTiO3.And through the bulk density and SEM analysis, when doping mole content x=0.2, better density products can be got.Adulterating appropriate amount of Mg2+,Ni2+ to ilmenite ZnTiO3 , it can improve thermal stability of ZnTiO3.And through the volume density and SEM analysis, when doping mole content x=0.2, better density products can be got. According to discuss the Zn(1-x )(Mg1/2Ni1/2)xTiO3 (x=0.05~0.3) property in different sintering temperature , the research results revealed that: doping appropriate Mg2+,Ni2+ can improve the dielectric property, sintering at 970℃dielectric property of Zn0.8(Mg1/2Ni1/2)0.2TiO3 dielectric property is as follows:εr≈25.3, Qf≈54000,τf=—12.3(ppm/℃)。...