【摘要】 对BaTiO3 和BaTiO3-Nb2 O5-Co2 O3 系组成进行了Dy2 O3 和La2 O3 稀土改性的研究 ,考察了该系统的介电温度特性和耐电性能 ,观察了样品的显微结构 ,讨论了Dy2 O3 和La2 O3 在改变BaTiO3 铁电温谱特性的作用 .结果表明 :Dy2 O3 和La2 O3 的掺杂效果存在差异 ,Dy2 O3掺杂明显促使BaTiO3 细晶化 ,而La2 O3 掺杂呈现出对BaTiO3 基介质材料的Curie峰更强的压峰和移峰效应 .在BaTiO3-Nb2 O5-Co2 O3-Dy2 O3 系统中可获取高介高压特性瓷料 ,其介电常数≈ 3 0 0 0 ,tgδ <1.5 % ,介电温谱符合“X7R”标准 ,击穿强度可达 7～ 8kV/mm更多还原

【Abstract】 The dielectric materials of BaTiO 3 and BaTiO 3-Nb 2O 5-Co 2O 3 system modified with rare earth oxides Dy 2O 3 or La 2O 3 were studied. Dielectric temperature dependence and breakdown voltage of the modified systems were measured. Microstructure of the sintered samples was observed. The role of Dy 2O 3 and La 2O 3 on changing dielectric temperature dependence of the BaTiO 3 dielectric ceramics is discussed. The experimental comparison shows that Dy 2O 3 doping can inhibit grain growth of BaTiO 3, whereas La 2O 3 doping has more considerable effect to shift and depress Curie peak of BaTiO 3. The dielectric ceramics with high dielectric constant( ε ≈ 3 000), low tg δ (tg δ <1.5%), high temperature stability and breakdown voltage( σ b≈7-8 kV/mm)can be obtained in the BaTiO 3-Nb 2O 5-Co 2O 3-Dy 2O 3 system.更多还原