Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5438890 | Ceramics International | 2017 | 32 Pages |
Abstract
This study investigated the effect of elemental crystal Ge or/and GeO2 doping on the microstructure and varistor properties of TiO2-Ta2O5-CaCO3 varistor ceramics, which were prepared via the traditional ball milling-molding-sintering process. X-ray diffraction, scanning electron microscopy, scanning transmission electron microscopy-energy dispersive X-ray spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy demonstrated that co-doping with Ge and GeO2 changed the microstructure of TiO2-Ta2O5-CaCO3 ceramics, thereby increasing the nonlinear coefficient and decreasing the breakdown voltage. The optimum doping concentrations of Ta2O5, CaCO3, Ge, and GeO2 exhibited the highest nonlinear coefficient (α=14.6), a lower breakdown voltage (EB=18.7 V mmâ1), the least leakage current (JL=10.5 μA cmâ2), and the highest grain boundary barrier (ΦB=1.05 eV). In addition, Ge and GeO2 function as sintering aids, which reduce the sintering temperature because of their low melting points.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Kunyong Kang, Zhifeng Zheng, Sida Xie, Jun Zhang, Kaimeng Xu, Lei Tao, Xuequan Rong, Zhefeng Xu, Jikang Yan, Guoyou Gan,