纳米晶CdFe_2O_4的制备与湿敏性能研究

Studies on synthesis and humidity-sensitive properties of nanocrystalline CdFe_2O_4

采用硬脂酸凝胶法化学工艺在较低温度下合成CdFe2 O4纳米晶材料。TG DTA热分析表明 :纳米晶CdFe2 O4在 410℃左右晶化形成 ;XRD、BET比表面吸附等技术表征结果表明 ,所合成纳米晶CdFe2 O4属立方尖晶石结构 ,平均晶粒度为15～ 2 3nm ,Cd2 + 适度过量对CdFe2 O4晶粒生长具有抑制作用。湿敏特性测试结果表明 ,纳米晶CdFe2 O4湿敏元件感湿灵敏度优于相应的常规陶瓷元件 ,Cd2 + 适度过量 (Cd2 + /Fe3 + >1/2 ) ,可达到调制纳米晶湿敏电阻值范围及减小材料湿滞的双重目的。初步探讨了过量Cd2 + 影响CdFe2 O4纳米晶材料湿敏性能的内在原因。

Nanocrystalline CdFe 2O 4 was synthesized by stearic acid gel method. The synthesized nanocrystalline was characterized by means of the thermogravimetry and differential thermal analysis (TG DTA),X ray diffraction (XRD) and specific surface area absorption (BET). The results of humidity sensitive characteristics investigation showed that the humidity sensitivity of nanocrystalline CdFe 2O 4 was greatly higher than of common CdFe 2o 4 ceramic sensor, and with increasing of Cd 2+ content (>1/2, molar ratio), humidity sensitive resisance of nanocrystalline CdFe 2O 4 was lowed and its hysterises was improved. Forthermore, inner reasons on excess Cd 2+ effecting humidity sensitive characteristics of nanocrystalline CdFe 2O 4 was proposed