英语翻译

英语翻译
Ceramic varistors based on ZnO–SnO2.求帮忙翻译这个题目的那篇英文文献.以下是摘要
Abstract
Model ceramic varistor formulations based on 98% ZnO–SnO2(plus 2% oxides of Bi,Co and Mn) were prepared by conven-tional powder processing routes; specimens were sintered at 1150–1275?C.The product density increased with SnO2content,but decreased with increase in sintering temperature.The microstructures contained ZnO,Zn2SnO4spinel and very small bismuth rich phases; with increasing Sn content the spinel became the dominant phase.From I–V measurements,the non-linear coefficients were found to be in the range 24–32.For all compositions,the values decreased with increasing sintering temperature; the maximum value was obtained with samples containing 20 mol% SnO2sintered at 1200?C.Breakdown fields were in the range 3000–11000 V/cm and increased with increasing tin content.Leakage currents were in the range 1–11 mA.Tin substitution for Zn appears to cause a strong donor effect.