自蔓延燃烧法合成ZnO粉体及其压敏电阻的制备

VARISTORS PREPARED BY SELF-PROPAGATING COMBUSTION ZnO POWDERS

以硝酸锌、尿素以及其它添加剂为原料,通过自蔓延燃烧法一次性合成了ZnO压敏电阻用掺杂纳米粉体。用X射线衍射、扫描电镜、比表面测试、激光粒度分析等手段对所制备粉体的性能进行了表征。研究了反应物质量比对粉体性能的影响,以及煅烧温度对ZnO压敏电阻电性能的影响,并对自蔓延燃烧合成反应进行了初步探讨。结果表明:在点火温度为600℃,尿素/金属离子盐质量比为1:1时,所制备的掺杂纳米ZnO粉体的综合性能最好。用此粉体制备的ZnO压敏电阻的电性能最佳,电位梯度为745.27V/mm,非线性系数为56.53,漏电流为6μA。

Using zinc nitrate, urea and additives as raw materials, doped ZnO nanopowders for varistors were prepared by the self-propagating combustion method. The powders were characterized by means of X-ray diffraction, scanning electron microscopy, specific surface area analysis and laser size analysis. The effects of addition amounts of urea on the properties of the powders and sintering temperature on the properties of ZnO varistors were studied. The mechanism of the reaction in the self-propagating combustion process was discussed. The results showed that doped ZnO powders prepared at 600℃ when the mass ratio of urea and metal salts is 1, possess good properties. A ZnO varistor with the best electronic properties was prepared by the powders, which had a potential gradient of 745.27 V/mm, a nonlinear coefficient of 56.53 and a leakage current of 6μA.