【摘要】 用反滴定化学共沉淀法制备了纳米尺寸尖晶石型的复合金属氧化物MgFe₂O₄粉体。用X射线粉末衍射分析、透射电镜等手段研究了其结构特性。MgFe₂O₄粉体颗粒均匀，700℃煅烧1 h粉体平均粒径约为20 nm。研究表明：煅烧温度对材料的结构及性能有较大的影响。以MgFe₂O₄纳米粉体为原料制备了旁热式气敏元件，测试了元件的敏感特性和响应恢复特性。结果显示，MgFe₂O₄是一种良好的n型半导体气敏材料，700℃煅烧1 h所得纳米粉体制作的元件在300℃工作温度时对CH₃COCH₃有较高灵敏度和良好的选择性，对体积分数为1 000×10_-6的CH₃COCH₃的灵敏度可达36.87。并对气敏机理给予了解释。更多还原

【Abstract】 MgFe₂O₄ composite oxide nano-powder of spinel-type was prepared by inverse titrating chemical co-precipitation method, and its microstructure was characterized by means of powder XRD and TEM. The powder with homogeneous grain size of about 20 nm of average diameter was obtained after calcining at 700℃ for 1h. The results show that sintering temperatures have great influence on microstructure and properties of the sample. The properties of MgFe₂O₄ gas sensors made from MgFe₂O₄ nano-powder were measured. MgFe₂O₄ is an excellent n-type semiconductor gas-sensing material, and the sensor prepared by MgFe₂O₄ powder calcined at 700℃ for 1h exhibits high sensitivity and good selectivity. The sensitivity of the sensor to CH₃ COCH₃ o 1000×10^-6 in volume at 300℃ operating temperature can reach to 36.87. The gas sensing mechanism is discussed.更多还原