Co^(2+)对Co_xFe_(3-x)O_4铁氧体结构与磁特性的影响  

Structural and magnetic properties of Co_xFe_(3-x)O_4 nanoparticles

作　　者：焦永芳[1] 李锐[1] 刘钧[2] 方庆清[1] 

机构地区：[1]安徽大学物理与材料科学学院,合肥230039 [2]皖西学院物理系,六安237031

出　　处：《功能材料与器件学报》2005年第4期481-484,共4页Journal of Functional Materials and Devices

基　　金：安徽省科学技术带头人项目(No.01080210);安徽省信息功能材料与器件实验室资助课题

摘　　要：采用化学共沉法制备了纳米尺度的钴铁氧体CoxFe3-xO4(x=0.2~1.0)粉料,并在1260-1340℃温度下进行了退火处理,利用X射线衍射仪(XRD)、振动样品磁强计(VSM)对样品的结构和磁性进行了测量和分析。实验结果表明,当钴含量高(x≥0.7)时样品形成了单一的具有尖晶石结构的钴铁氧体,而钴含量x<0.7时样品生成了尖晶石结构的钴铁氧体相和α-Fe2O3相。CoxFe3-xO4的比饱和磁化强度σs随x的增加呈现出了先增后减的趋势,在x=0.8时出现峰值;x=0.5~0.8范围内,矫顽力Hc随钴含量的增加有所下降,随后迅速增加,在x=1.0附近能同时得到较大的σs和Hc值。Cobalt ferrite CoxFe3-xO4（ x =0. 2 - 1. 0） coprecipitation method and annealed at temperatures magnetic properties of the samples were analyzed nanocrystalline powders were prepared by chemical from 1260℃ to 1340℃ in air. The structural and through the X -ray diffraction （XRD）patterns and vibrating sample magnetometer （VSM） . The experimental results show that monophase CoxFe3-xO4 ferrites with a spinel structure are formed with high Co^2＋. content（ x≥0. 7 ） ,while with the lower Co^2＋ content （x 〈0. 7）CoxFe3-xO4 phase and α- Fe2O3 phase are obtained at the same time. The specific saturation magnetization climbs up at first and falls down with the cobalt content increasing. The maximum of σs is attained at the x = 0. 8. In the range of x =0. 5 - 0. 8, the coercivity Hc decreases with the increase of x, then climbs up rapidly. Higher σs and Hc can be achieved simultaneously at about x = 1. 0.

关 键 词：铁氧体 化学共沉法 比饱和磁化强度 矫顽力 

分 类 号：TM277[一般工业技术—材料科学与工程]