Low-Temperature Sintering and Electrical Properties of ZnO-Bi2O3-TiO2-Co2O3-MnCO3-Based Varistor with Bi2O3-B2O3 Frit for Multilayer Chip Varistor Applications

摘要: The effects of a Bi2O3–B2O3 frit (denoted as BiBF) on the densification, phase transformation, microstructure, and nonlinear electrical properties ZnO–Bi2O3–TiO2–Co2O3–MnCO3 (ZBTCM)-based varistors have been investigated. varistor ceramic with addition >2 wt% BiBF can be sintered at 900°C 96.3% theoretical density was achieved. SEM revealed that microstructure ceramics 2 is uniform, an average grain size 13.5 μm. No porosity observed. typical ZnO–Bi2O3–TiO2-based compositions were detected for all but formation secondary phase, Bi4B2O9, became apparent when 4 added. Bi4B2O9 crystallized from frit, acting potential barrier boundary, increases interface states Ns, height Φb, plays important role in improving ceramics. However, large amount will detrimental. Optimum exhibited 900°C, E1 mA=124.9 V/mm, α=46.2, JL=0.2 μA/cm2. reactivity Ag also studied. excellent low sintering temperature, coupled chemical compatibility Ag, suggest aids great using base metal inner electrodes low-voltage MLV fabrication.