溶液包裹法制备低压氧化锌压敏陶瓷

Low Voltage ZnO Varistor Fabricated by Solution-Coating Method

报道了一种以掺杂物溶液包裹ZnO粉末制备高性能ZnO低压压敏陶瓷的新方法。采用该方法与常规固相反应法分别制备了低压ZnO压敏复合粉体。运用XRD、SEM手段对两种方法制备的粉体及烧结试样进行了表征,并对烧结试样密度及电学性质进行了测定。结果显示:与固相反应法所制试样相比,溶液包裹法制得的试样的ZnO晶粒显著变大,均匀性和致密性也得到明显改善;梯度电压明显降低,非线性系数提高,漏电流减小,实用性大幅度提高。可见,这种新颖的溶液包裹方法较常规固相反应法更适合于ZnO低压压敏陶瓷的制备。分析认为,溶液包裹法的这些优点归因于制备过程中掺杂物包裹层的纳米效应导致的ZnO陶瓷微观结构均一性的提高。

The solution coating route, by coating ZnO powder with a mixed solution of dopants, was developed for preparing a high performance low voltage ZnO varistor and compared with the conventional mixed-oxide route. The microstructure observations and electrical characteristics show that the specimens prepared by the solution coating route have bigger grain sizes, higher densities, more evenly distributed intergranular phases, lower threshold voltage, higher non-linearity coefficient and smaller leakage current than those by the conventional mixed-oxide route, indicating that the solution coating route is a better way of preparing low voltage ZnO varistor.