摘要
利用物理特性测试仪对共沉淀法制备的Cr3 + 掺杂NiFe2 O4的磁性能进行测试 ,发现掺杂Cr3 + 并经 35 0、6 0 0℃焙烧的NiFe2 O4样品 ,饱和磁化强度Ms和剩磁Mr随掺杂量的增加而下降 ,矫顽磁场强度Hc随掺杂量的增加而增加 .XRD平均晶粒测试结果显示 ,样品的平均晶粒大小随掺杂量的增加而减小 .在共沉淀过程掺杂的Cr3 +经 6 0 0℃热处理后已进入NiFe2 O4晶格 .晶格中的Cr3 + 对NiFe2 O4分解CO2 的H2 /CO2 循环反应性能产生很大影响 ,纯NiFe2 O4循环反应 15次失活 ,而掺 4 %Cr3 + 的NiFe2 O4循环反应 5
Cr3+ doping NiFe2O4 was prepared by mixed ions co-precipitation. The magnetic properties were investigated by the physical property measurement system. The saturation magnetization Ms, remanent magnetization Mr and coactivity Hc were calculated from 5 K hysteretic loops of different Cr3+ doping content NiFe2O4 after being annealed at 350 and 600degreesC. With the increasing of Cr3+ content, for 350degreesC annealing samples, Ms decreased from 32.49 to 18.11 emu/g, Mr decreased from 9.39 to 3.72 emu/g and Hc increased from 230 to 2500 Oe, for 600degreesC annealing samples, Ms decreased from 44.59 to 21.73 emu/g, Mr decreased from 14.04 to 10.32 emu/g and Hc increased from 350 to 720 Oe, respectively. It was obviously shown that the magnetic properties of samples change corresponded to the doping content of Cr3+. XRD measurement also showed that the crystallite size and cell parameter of samples decreased as the increasing of Cr3+ doping content. These results affirmed that Cr3+ entered the lattice of NiFe2O4 after being annealed at 600degreesC. The existence of Cr3+ in the structure of NiFe2O4 dramatically raised the stability of the spinel structure and CO2 cycle decomposition times. Pure NiFe2O4 lost its activity just after 15 cycle reactions, and the phase abundance of NiFe2O4 remained about 5%, while Cr3+ doping NiFe2O4 still had some activities after 50 reaction times and the phase abundance of NiFe2O4 still had 20%.
基金
ProjectsupportedbytheNationalNaturalScienceFoundationofChina (2 0 2 770 33)
