Abstract：ZnO linear resistors doped with different Al2O3 contents of 3.5%，4.0%，4.5% and 5.0% were prepared by high energy ball milling at different sintering temperature of 1 250, 1 300 and 1 350 ℃. The microstructure and the crystal characteristics were investigated by scanning electron microscope(SEM) and X-ray diffractions. The influences of Al2O3 content and sintering temperature on the dielectric and varistor characteristics of the linear resistors were also investigated. The results show that the main phase of ZnO linear resistor doped by Al2O3 is ZnO with small amount of second phase Zn2SiO4. When the molar fraction of Al2O3 is 3.5% at sintering temperature of 1 350 ℃, the best performance of linear resistance is obtained with nonlinear coefficient of 1.00. The dielectric constant of ZnO linear resistor is not influenced greatly by the increasing of dopant Al2O3 contents, but suffered significant impact by sintering temperature.
2014, Vol. 35 
