掺杂Mg^(2+)对NiFe_2O_4晶体结构及气敏性的影响  

Influence of blending Mg^(2+) on crystal structure and gas sensitivity of NiFe_2O_4

作　　者：焦万丽[1] 张磊[1] 

机构地区：[1]山东理工大学材料科学与工程学院,山东淄博255049

出　　处：《沈阳工业大学学报》2010年第4期380-384,共5页Journal of Shenyang University of Technology

基　　金：山东省中青年科学家科研奖励基金资助项目(2006BS04035)

摘　　要：针对纯的镍铁尖晶石纳米材料对气体灵敏度较低问题,以硝酸铁、硝酸镍和硝酸镁作为反应物,柠檬酸作为凝胶剂,采用溶胶凝胶结合自蔓延燃烧工艺合成Ni1-xMgxFe2O4型纳米粉体,研究了金属镁离子掺杂对镍铁尖晶石晶体结构及气体灵敏度的影响.x-射线衍射仪(XRD)分析和扫描电子显微镜(SEM)分析结果表明:干凝胶在250℃自燃所得的粉体即为NiFe2O4尖晶石相,Mg2+在NiFe2O4晶格中优先占据B位,部分占据A位.采用600℃热处理后的样品颗粒尺寸为30～50nm.气敏性能测试结果表明:当x为0.2,最佳工作温度为300℃时,Ni1-xMgxFe2O4型气敏元件对丙酮气体的灵敏度最高.In order to improve the gas sensitivity of pure nickel ferrite nano-material,Ni1-xMgxFe2O4 nano-powder was prepared by sol-gel plus self-propagating combustion method with taking iron nitrate,nickel nitrate and magnesium nitrate as reactants and citric acid as gel. The influence of blending Mg2＋ on both crystal structure and gas sensitivity of nickel ferrite was characterized. The XRD and SEM analysis results indicate that the powder synthesized by self-propagating combustion of dry gel at 250℃ is single NiFe2O4 phase,and Mg2＋ ions preferentially occupy the B sites and partially occupy the A sites in the crystal lattice of NiFe2O4. The particle size of the sample heat-treated at 600℃ is about 30 to 50nm. The testing results of gas sensitivity reveal that when x is 0.2 and the optimal operating temperature is 300℃,the sensitivity of Ni1-xMgxFe2O4 gas sensor to acetone gas is the highest.

关 键 词：纳米粉体 镍铁尖晶石 镁离子 掺杂 溶胶凝胶法 自蔓延燃烧 晶体结构 灵敏度 

分 类 号：TB34[一般工业技术—材料科学与工程]