SnO₂ Doping Effect on the Microstructural and Electrical Behavior of ZnO nanoparticles-Bi₂O₃ Based Varistor Ceramics

Abstract

In the current study, ZnO-Bi2O3 varistors manufactured from ZnO nanoparticle size and doped with SnO2 were processed by the ceramic industrial technique. The impact of the various SnO2 concentration upon the sintering, microstructural improvement and nonlinearity characteristic of the varistor system was investigated. Different SnO2 concentration was found to possess considerable influences on the varistors, particularly on improving ZnO grains growth at a lower SnO2 amount. But, the adding of greater contents of SnO2 leads to inhibit the ZnO grain growth via the raising percentage of Zn2SnO4 type spinel phase. In discs with a Sn/Bi less than 1.5 mol%, the pyrochlore phase forms and bounds all the SnO2, whereas excess Bi2O3 leads to the formation of a liquid phase at 740 °C which promotes sintering process. For Sn/Bi more than 1.5 mol%, all the Bi2O3 is bounded in Bi2Sn2O7 pyrochlore phase and sintering process is prevented. X-ray diffraction investigated that additive of SnO2 to the ZnO-Bi2O3 varistor sample caused the structure of the Bi2Sn2O7 type pyrochlore phase and the Zn2SnO4 type spinel phase during the sintering step. The SnO2 adding furthermore noticeably affected the electrical behaviors of the sample with a significant rise in the breakdown voltage with increasing the SnO2 doping more than 1.5 mol%. The resistivity also achieved an obvious increase with increase the SnO2 doping contents. Moderate SnO2 doping enhanced the nonlinear properties of the ZnO-Bi2O3 varistor system, while a significant amount of SnO2 causing its deterioration.

Structural, optical, and dielectric properties of hydrothermally synthesized SnO2 nanoparticles, Cu/SnO2, and Fe/SnO2 nanocomposites

“…Tin oxide (SnO 2 ) is an n-type semiconductor characterized by a wide band gap (∼3.6 eV) and electron mobility of 160 cm 2 V −1 s −1 at room temperature (RT) as a result of Sn interstitial defects and oxygen vacancies [9][10][11]. The incorporation of 3d transition metal (M) into SnO 2 to form M/SnO 2 composites is commonly utilized to reduce their particle size and hence enhance their physical and chemical properties [12][13][14].…”

Preparation and Characterization of FTO/nZnO/CH3NH3PbI3/C/Cu Perovskites Solar Cell

“…It is well known that, ZnO is considered one of the metal oxide varistors due to the nonlinear behavior of resistance R as a function of applied voltage [2,34,35]. Figure (19 c, f) shows the resistance change as a function of the applied voltage of the cell, where the bottom layer of the cell is ZnO nanowires.…”