摘要
用溶胶 -凝胶法制备了CdFe2 O4 及其掺银纳米粉 ,并对其制备条件、物相组成、微结构、电导和气敏性能作了系统研究。结果表明 :35 0℃下预烧 2h进一步除尽残存柠檬酸的凝胶粉于80 0℃下热处理 2h可得纯相掺银纳米粉Cd1-xAgxFe2 O4 (0≤x≤ 0 .0 4 ) ;电导测量显示 ,该材料呈表面电阻控制的n型半导体导电行为 ,由于AgCd× 电离出的空穴h 对材料中导带自由电子的湮灭 ,使得掺银固溶体的导电性远小于同温下的纯相CdFe2 O4 ;Cd0 .98Ag0 .0 2 Fe2 O4 纳米粉制作的元件在330℃下对 4 5 μmol/LC2 H5OH的灵敏度为相同浓度干扰气体Petrol的 11倍多。有望开发为一类新型C2 H5OH信息敏感材料。
CdFe 2O 4 and its Ag + doped nano powders were prepared by sol gel method, the preparation conditions, phase constituents, microstructures, conductance and gas sensing properties were also investigated. The results show that Cd 1- x Ag x Fe 2O 4(0 ≤ x ≤0.04) solid solution nano materials can be obtained when gel powder is calcined for 2h at 800℃, which is made from preheating gels at 350℃ for 2hr and gets rid of surviving lemon acid. Measuring conductance shows that the material assumes behavior of the surface resistance controlled n type semiconductor because of ionization of defect Ag Cd × (→Ag Cd ′+ h ·). The positive holes nullify free electrons (h ·+ e′→null). The conductance of Ag + doped solid solution is much lower than that of pure CdFe 2O 4 at same temperature; Sensitivity of the element made from Cd 0.98 Ag 0.02 Fe 2O 4 to 45 μmol/L C 2H 5OH is 11 times larger than the petrol interfering gas of same concentration at 330℃. It is hoped to develop a new type information sensitive material of C 2H 5OH.
基金
安徽省教育厅自然科学基金资助项目&&
