纳米ZnFe2O4的制备及其气敏性能研究

采用柠檬酸盐热解法制备出纳米ZnFe2O4粉末,其物相纯净,颗粒分散性好,尺寸小于50 nm.实验结果表明,ZnFe2O4晶粒生长随焙烧温度升高存在两个生长阶段,即快速生长I区和正常生长II区.随着烧结温度的升高,厚膜元件电阻快速下降.ZnFe2O4厚膜元件对苯及其衍生物蒸汽有较高的敏感度,且存在最佳工作温度和最佳烧结温度,分别为360℃和500℃.

Fabrication and Gas Sensitivity of Nano-Sized ZnFe2O4 Powder

Raw pow ders of nano ZnFe2O4 have been obtained by the cit rate pyroly sis. T he compo sit io n and st ructure of the pow ders have been invest igated by the means of XRD and FESEM. T he as??received Zn?? Fe2 O4 pow ders hav e pur e spinel??type st ructur e and the every size of the spherical par ticles are below 50 nm w ith g ood dispersity . T he inf luence of temperature o n the st ructur e, resistance, gas sensit iv it ies ar e test?? ed. T he result s demonst rate that as the calcining temperature increases, the crystal grow th of ZnFe2 O4 has tw o g row th processes, stage of quick gr ow th and stag e o f normal growth. While the sinter ing temperature increases, the resistance of ZnFe2 O4 sensors decreases dramat ically. T he sensit ivit ies of ZnFe2 O4 sensors to benzene and its derivat ives are hig h, and the sensors hav e opt imal o perat ing temperature and opt imal sintering temperature, 360 ?? and 500 ?? separately.