Effect of aluminum addition on electrical properties, dielectric characteristics, and its stability of (Pr, Co, Cr, Y)-added zinc oxide-based varistors

Bulletin of materials science

Choon-W Nahm¹ 

[1] Department of Electrical Engineering, Dongeui University, Busan 614-714, Republic of Korea$$Department of Electrical Engineering, Dongeui University, Busan 614-714, Republic of KoreaDepartment of Electrical Engineering, Dongeui University, Busan 614-714, Republic of Korea$$

关键词: Aluminum;    electrical properties;    dielectric characteristics;    varistors;    stability.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

The electrical properties, dielectric characteristics, and its stability against d.c. accelerated aging stress of (Pr, Co, Cr, Y)-added zinc oxide-based varistors were investigated for different aluminum concentrations under a sintering temperature of 1280°C. As the aluminum concentration increased, the average grain size (ð‘�??) increased in the range of 4.3â€�??5.5 𝜇m and the sintered density increased in the range of 5.63â€�??5.67 g/cm³. As the aluminum concentration increased, the breakdown field decreased in the range of 6327â€�??710 V/cm and the maximum nonlinear coefficient (46.9) was obtained for 0.005 mol% in aluminum concentration, further additions impaired the nonlinear properties. As the aluminum concentration increased, the apparent dielectric constant increased in the range of 500.5â€�??1327.4 and dissipation factor increased in the range of 0.00493â€�??0.0724. The varistor added with 0.001 mol% Al exhibited the highest stability for 𝐸â€�?�ð�? characteristics in which %ð›�? 𝐸_{1 mA} is +1.4% and %ð›�? ð›�? is â€�??5.7%, under stress state of 0.95 𝐸_{1 mA}/150° C/24 h.

【 授权许可】

Unknown