Sm^(3+)含量对BaSm_xFe_(12-x)O_(19)(x≤0.4)铁氧体纳米纤维结构和磁性能的影响

Effect of Sm^(3+) Substitution on Structure and Magnetic Properties of BaSm_xFe_(12-x)O_(19)(x≤0.4) Ferrite Nanofiber

以金属盐和柠檬酸为原料,采用溶胶-凝胶法制备直径在1μm以内的BaSmxFe12-xO19(x≤0.4)铁氧体纳米纤维。采用FTIR、SEM、EDS、XRD和VSM对BaSmxFe12-xO19(x≤0.4)铁氧体纳米纤维进行表征。结果表明,经950℃烧结后,BaSmxFe12-xO19(x≤0.4)铁氧体已成相,且其微观结构和磁性能受掺杂离子浓度的影响。随着Sm3+含量的增加,饱和磁化强度呈先减小后增大的趋势,而矫顽力随Sm3+含量增加而逐渐增大,由x=0时的348.8 kA.m-1增大到x=0.4时的427.5 kA.m-1。与之相对应,在液氮(77 K)条件下,纤维的饱和磁化强度有显著的提高,而矫顽力则明显下降,这主要是由于纳米晶的表面自旋提高造成的。

BaSmxFe12-xO19（x≤0.4） ferrite nanofibers below 1 μm were prepared by sol-gel method from starting reagents of metal salts and citric acid.These nanofibers were characterized by FTIR,SEM,EDS,XRD and VSM.The results show that the BaSmxFe12-xO19（x≤0.4） ferrites were obtained at 950 ℃.The microstructure and magnetic property of nanofibers are mainly influenced by Sm3＋ contents.The specific saturation magnetization of BaSmxFe12-xO19 ferrite nanofiber calcined at 950 ℃ initially decreases and then increases with a further Sm content,while the coercivity exhibits a continuous increase from 348.8 kA·m-1（x=0） to 427.5 kA·m-1（x=0.4）.The differences of magnetic properties are attributed to surface spin.