The microstructure and electrical properties of ZnO-Bi2O3-Yb2O3 based varistor ceramics were investigated with various temperature effects from 900°C to 1050°C.From the results,it was observed that the incre...The microstructure and electrical properties of ZnO-Bi2O3-Yb2O3 based varistor ceramics were investigated with various temperature effects from 900°C to 1050°C.From the results,it was observed that the increase of sintering temperature offers a reduced capacitive effect from 0.460 nF to 0.321 nF.Furthermore,the grain sizes of varistors were varied from 6.8μm to 9.8μm.The consequence of such smaller grain sizes provided a better voltage gradient of about 895 V/mm for the disc sintered at 900°C and fallen drastically to 410 V/mm for the sample sintered at 1050°C.In addition,there was an increase of non-linearity index to a maximum value of 36.0 and reduced leakage current of 0.026 mA/cm2.However,the density of the varistor decreased with an increase of temperature from 5.41 g/cm3 to 5.24 g/cm3.With this base,the influence of varistor capacitance and high voltage gradient were scrutinized and it led an improved transition speed of the varistor assembly from non-conduction to conduction mode during intruding nanosecond transients.展开更多
文摘The microstructure and electrical properties of ZnO-Bi2O3-Yb2O3 based varistor ceramics were investigated with various temperature effects from 900°C to 1050°C.From the results,it was observed that the increase of sintering temperature offers a reduced capacitive effect from 0.460 nF to 0.321 nF.Furthermore,the grain sizes of varistors were varied from 6.8μm to 9.8μm.The consequence of such smaller grain sizes provided a better voltage gradient of about 895 V/mm for the disc sintered at 900°C and fallen drastically to 410 V/mm for the sample sintered at 1050°C.In addition,there was an increase of non-linearity index to a maximum value of 36.0 and reduced leakage current of 0.026 mA/cm2.However,the density of the varistor decreased with an increase of temperature from 5.41 g/cm3 to 5.24 g/cm3.With this base,the influence of varistor capacitance and high voltage gradient were scrutinized and it led an improved transition speed of the varistor assembly from non-conduction to conduction mode during intruding nanosecond transients.
