M型锶铁氧体纳米纤维静电纺丝和磁性能

Fabrication and Magnetic Property of M-type Strontium Ferrite Nanofibers by Electrospinning

以聚乙烯吡咯烷酮(Polyvinylpylrrolidone,PVP)和金属盐为原料,采用静电纺丝法制备了SrFe12O19/PVP复合纤维前驱体,前驱体经焙烧后得到M型锶铁氧体纳米纤维.通过FTIR、TG/DSC、XRD、SEM和VSM技术对复合纤维前驱体及所制备的M型锶铁氧体纳米纤维进行了表征.结果表明,复合纤维前驱体的直径与溶液中金属盐浓度有关,随盐浓度的升高纤维直径增大;经800℃焙烧2h后,得到纯相M型锶铁氧体纳米纤维,直径在100～150nm,组成纤维的平均晶粒大小约为49nm,且随焙烧温度的升高,晶粒长大;经1000℃焙烧2h后得到的锶铁氧体纤维的磁性能最佳,此时纤维平均直径约为100nm,晶粒尺寸约为61nm,室温下测得的饱和磁化强度为68.5A.m2/kg,矫顽力为503kA/m.

SrFe12O19/PVP composite fiber precursors were prepared by electrospinning with ferric nitrate,strontium nitrate and polyvinylpyrrolidone（PVP） as starting reagents.M-type strontium ferrite nanofibers are obtained subsequently from calcination of these precursors at 800-1100℃.The composite fibers and M-type strontium ferrite nanofibers are characterized by FTIR,TG/DSC,XRD,SEM and VSM.The diameters for the composite fibers are influenced by the metal salt concentration in solution during the electrospinning process and increase from about 300nm to 550nm corresponding the metal salt concentration in the range from 12.5wt% to 23.1wt%.The M-type strontium ferrite nanofibers calcined at 800℃ for 2h are characterized with a diameter range of 100nm to 150nm,crystalline size around 49nm which will increases with the increase of calcination temperature.The saturation magnetization of M-type strontium ferrite nanofibers tends to increase with the crystalline size increasing.The coercivity increases as the crystalline size less than the critical size of a single-domain of 61nm while decreases as the crystalline size larger than 61nm.The M-type strontium ferrite nanofibers calcined at 1000℃ for 2h,with an average diameter of about 100nm and crystalline size of around 61nm,exhibit the best magnetic properties at room temperatures,with saturation magnetization of 68.5A·m2/kg and coercivity of 503kA/m,respectively.