Preparation And Properties Of Y ^{3 +} Doped TiO 2 Pressure Sensitive Ceramics

TiO2is a novel low-breakdown voltage varistor ceramic. T1O2has a wider application field because the technology of preparation is simple and the cost is low. The structure of rutile titanium dioxide is steady, the coordination number of Ti4+is six and the radius of Ti4+is0.064nm. Doping is necessary for TiO2ceramics to get better performances; Sintering temperature, radius and valence of doped ions have obvious influence on microstructure, chemistry composition and electrical properties of TiO2varistor ceramics. In the paper, the microstructure and electrical properties in (1)undoped,(2) single donor V5+,(3) single acceptor Y3+,(4)(V5+, Y3+) codoped Titanium dioxide ceramics were mainly investigated.Firstly, Titanium dioxide samples were prepared by conventional electronic ceramic technology at1100℃,1200℃,1300℃and1400℃. Microstructure, chemistry composition and electrical properties of TiO2ceramics were tested via SEM, XRD and CLJ1001.The studied results indicate that a small amount of V2O5doped is good for TiO2varistor semiconducting and reduce the sintering temperature without the second phase, with the increase of doping varistor voltage V1mA reduce, when the doping content is excessive, we found the presence of a small amount of V2Ti3O9phase which go against TiO2varistor semiconducting, with the increase of doping V1mA increases, minimum V1mA is29.9V when the temperature is1200℃, the doping of V2O5is0.35mol%, but not conducive to improve the nonlinear coefficient a, the nonlinear coefficient of single doped V2O5in the2-4range.A small amount of Y2O3doped go against TiO2varistor semiconducting with the existence of Y2Ti2O7phase, with the increase of doping varistor voltage V1mA increases, generally, the V1mA is large, but the second phase precipitates at the grain boundaries make the grain boundary layer gradually to compact and the height of grain boundary barrier to rise and to improve the density and nonlinear coefficient of TiO2varistor ceramics, the highest density can reach99.3%, non-linear coefficient within3to5.In order to low varistor voltage and high nonlinear coefficient about TiO2varistor, co-doped Y2O3and V2O5have been usesd in the experiment, the study found that the lowest V1mA is38.1V and nonlinear coefficient is4.6when the temperature is1200℃, V2O5is0.35mol%and Y2O3is0.25mol%, the electrical properties of TiO2varistor ceramics is better at this point.