La-Co共掺杂的M型锶铁氧体纳米纤维的制备和磁性能

Preparation and Magnetic Properties of La-Co Co-Doped M-Type Strontium Ferrite Nanofibres

以聚乙烯吡咯烷酮(PVP)和金属盐为原料,采用静电纺丝、溶胶-凝胶技术以及随后的热处理工艺,制备了La、Co共掺杂的M型锶铁氧体Sr1-xLaxFe12-xCoxO19(x=0.12)(SLFC)纳米纤维.利用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和超导量子干涉仪(SQUID)技术对纳米纤维样品的结构、形貌和磁学性能进行了观测,系统地研究了不同温度下样品的磁性能变化.结果表明:经过950°C焙烧2h后,得到纯相的M型锶铁氧体纳米纤维,纤维呈竹节状结构,直径约55nm;室温下测得矫顽力(Hc)为498.53kA·m-1,饱和磁化强度(Ms)为70.76A·m2·kg-1,剩磁(Mr)为36.35A·m2·kg-1,这比未掺杂SrFe12O19(SF)时纳米纤维的磁性能有明显的改善,并且与在相同温度下制得的相应纳米粉体样品相比,磁性能明显提高.

Polyethylene pyrrole（PVP）and metal nitrate were used as precursors,La and Co co-doped M-type strontium ferrites Sr 1-x La x Fe 12-x Co x O 19 （x=0.12）（SLFC）were prepared by electrospinning,sol-gel, and subsequent heat treatment processing.The crystal structure,morphology,and magnetic properties of the samples were studied by means of X-ray diffraction（XRD）,scanning electron microscopy（SEM）, transmission electron microscopy（TEM）,and superconducting quantum interference device（SQUID）.The influences of the variation of sintering temperature on the magnetic properties of SLFC were systematically investigated.The experimental results show that the optimum values of the magnetic properties were obtained at 950°C for 2 h,and the coercivity（H c ）,saturation magnetization（M s ）,and remanence（M r ）values of the samples were 498.53 kA·m -1 ,70.76 A·m 2 ·kg -1 ,and 36.35 A·m 2 ·kg -1 , respectively.Pure-phase bamboo-like SLFC nanofibres with diameter of about 55 nm were fabricated. The magnetic properties of undoped SrFe 12 O 19 （SF）were improved obviously,and the SF nanofibres exhibited better magnetic properties than the corresponding nanoparticles obtained by the sol-gel processing.