(Nb,Mg,Al)多元掺杂对ZnO压敏材料电学性质的影响

Electrical Properties of ( Nb, Mg, Al )-doped ZnO Based Varistor

研究了(Nb,Mg,Al)多元掺杂对ZnO压敏材料电学性能的影响。施主Nb离子的掺杂显著提高了压敏电阻的势垒高度,这与它能提供晶界势垒形成所必需的正电荷和负电荷直接相关。小半径离子Mg和Al易于处在ZnO的填隙位置,适量的掺杂也能提高晶界势垒高度,这与处在填隙位置的金属离子能提供正电荷和负电荷有关。而且填隙掺杂还能有效地改善陶瓷的致密度和均匀度,从而降低了ZnO压敏电阻漏电流、残压比和提高了非线性。(Nb,Mg,Al) 多元掺杂的ZnO压敏电阻的漏电流、残压比和非线性系数分别达到了 0.3 mA、V40kA/V1mA 2.5和a 110。

Investigated were the effects of doping ( Nb, Mg, Al ) on the electrical properties of ZnO based varistors. Doping donor Nb increased remarkably the height of the varistor grain boundary barrier whose formation was related to the presence of positive and negative charges provided by donor. Properly doping Mg and Al with smaller ionic radius can be raised the height of the varistor grain boundary barrier which was related to the presence of positive and negative charges provided by donors as interstitials. The interstitials not only imporoved the density and homogeneith of varistor, but also reduced the leakage current and residual voltage ratio, and enhanced nonlinearity. The leakage current, residual voltage ratio and nonlinear coefficient are found to be 0.3 mA, 2.5 and 110, respectively.