Magnetic properties of samarium and gadolinium co-doping Mn-Zn ferrites obtained by sol-gel auto-combustion method  

作　　者：季必发 田长安 张全争 吉冬冬 阳杰 谢劲松 司靖宇 

机构地区：[1]Department of Chemistry and Materials Engineering, Hefei University [2]Institute of Nano Science and Technology, University of Science and Technology of China [3]State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences

出　　处：《Journal of Rare Earths》2016年第10期1017-1023,共7页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(51102073);the Natural Science Foundation of Education Department of Anhui Province of China(KJ2015A232,KJ2015B1105906);the Natural Science Foundation of Anhui Province of China(1308085QB35);the research fund of State Key Laboratory of Structural Chemistry(20110012);Anhui Province Outstanding Young Teachers Visit Abroad Training Projects(gxfxZD2016220);the Outstanding Young Talent Project in Colleges and Universities of Anhui Province

摘　　要：Mn-Zn ferrites doped with different contents of Sm^（3＋） and Gd^（3＋） ions were prepared by sol-gel auto-combustion method and characterized by Fourier transform infrared spectroscopy（FTIR）, thermogravimetric analysis（TG）, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and vibrating sample magnetometer（VSM）. When samples were calcined in a relatively low temperature below 1100 °C, secondary phases（α-Fe_2O_3） could be identified. Therefore, in order to acquire pure and better crystallinity, the suitable calcining temperature of powders was selected at 1200 °C. It was also found that all the samples consisting of ferrite phases of typical spinel cubic structure and average crystallite sizes between 31.5 and 38.2 nm were obtained after calcining at 1200 oC for 4 h. The lattice parameters increased almost linearly with increasing Sm content. A dense microstructure was obtained after sintering at 1250 °C for 4 h. Through the analysis of magnetic properties, hysteresis loops for all the samples were narrow with low values of coercivity and retentivity, indicating the paramagnetic nature of these samples. And saturation magnetization Ms strongly depended on the type of additive to reach a maximum of 47.99 emu/g for x=0.015, which showed a great promise for hyperthermia applications.Mn-Zn ferrites doped with different contents of Sm^（3＋） and Gd^（3＋） ions were prepared by sol-gel auto-combustion method and characterized by Fourier transform infrared spectroscopy（FTIR）, thermogravimetric analysis（TG）, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and vibrating sample magnetometer（VSM）. When samples were calcined in a relatively low temperature below 1100 °C, secondary phases（α-Fe_2O_3） could be identified. Therefore, in order to acquire pure and better crystallinity, the suitable calcining temperature of powders was selected at 1200 °C. It was also found that all the samples consisting of ferrite phases of typical spinel cubic structure and average crystallite sizes between 31.5 and 38.2 nm were obtained after calcining at 1200 oC for 4 h. The lattice parameters increased almost linearly with increasing Sm content. A dense microstructure was obtained after sintering at 1250 °C for 4 h. Through the analysis of magnetic properties, hysteresis loops for all the samples were narrow with low values of coercivity and retentivity, indicating the paramagnetic nature of these samples. And saturation magnetization Ms strongly depended on the type of additive to reach a maximum of 47.99 emu/g for x=0.015, which showed a great promise for hyperthermia applications.

关 键 词：Mn-Zn ferrites co-doping sol-gel auto-combustion method microstructure magnetic properties rare earths 

分 类 号：TM27[一般工业技术—材料科学与工程]