【作者】 王绍刚； 常爱民； 张慧敏； 赵青；

【Author】 WANG Shao-gang~(1,2) CHANG Ai-min~1 ZHANG Hui-min~1 ZHAO Qing~1 (1.Xinjiang Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Urumqi 830011,China; 2.Graduate School of the Chinese Academy of Sciences,Beijing 100049,China)

【机构】 中国科学院新疆理化技术研究所；

【摘要】 采用 Pechini 法,成功制备了 Mn_0．43Ni_0．9CuFe_0．67O₄纳米粉体。聚合前驱体在400～700℃下煅烧,采用热重差热分析（TG-DTA）、红外光谱（IR）、X 射线衍射（XRD）、粒度分布和扫描电镜 （SEM）对产物进行了表征。煅烧后,在900～1200℃烧结,测试了烧结陶瓷的电学性能参数：电阻率ρ和材料常数 B。结果表明,粉体的分解温度为300℃,由无定形相开始结晶；晶体结构不同于传统 NTC 材料的单一尖晶体结构,而是尖晶石相和单斜 CuO 相组成的固溶体；单斜 CuO 相对陶瓷的电学性能有较大影响。烧结性质表明,最佳烧结温度为1100℃,致密度为96％,ρ_25℃为 600Ω·cm,材料常数 B_25℃/50℃为2000。更多还原

【Abstract】 Mn_0.43 Ni_0.9 CuFe_0.67 O₄ nano-powders were synthesised by the Pechini method for the first time.A spinel-type phase,with a solid solution,was attained from calcining of the polyme- rized gel precursor at 400～700℃.The thermal evolution,surface morphology,and structural behavior were studied by TG-DTA,SEM,XRD and FT-IR.The electrical properties,the resis- tivity ρ and the materials constant B value,were also studied after sintering at 900～1200℃.It is found that the material decomposes upon heating above 300℃.The monoclinic structure of CuO is found to be coexistent with the spinel-type phase in both the calcined powders and the sintered ceramics.The electrical properties are deeply affected by the crystal phase of CuO.The ceramics sintered at 1100℃ shows the best electrical properties as well as the density,of which the rela- rive density is about 96%.The_ρ25℃ is about 600Ω·cm and B_25℃/50℃ is about 2000.更多还原