一维钡铁氧体纳米线的制备及操控

Preparation of One-Dimensional Nanostructures BaFe_(12) O_(19) and Study with Magnetic Manipulation

采用Sol-gel法,以自制的AAO模板制备了直径40～60nm,长度为150～200nm的一维BaFe12O19纳米线。利用X射线衍射(XRD),场发射扫描电镜(FESEM),振动样品磁强计(VSM)对BaFe12O19纳米线的组成、形貌与磁性能进行了研究。在外磁场的驱动下,对一维BaFe12O19纳米线进行操控。研究发现:BaFe12O19纳米线的易磁化方向平行其轴线方向,且操控后,BaFe12O19纳米线定向连接成"链",当磁场与BaFe12O19纳米链阵列平行(∥)时,纳米链的剩余磁化强度(Mr)、饱和磁化强度(Ms)和最大磁能积(BH)m都得到增强。矫顽力(Hc)由3.98×105A/m增大至5.01×105A/m,矩形比为0.9,可成为优异的高密度垂直磁记录材料。

BaFe12O19 nanowires were prepared into homemade AAO by the sol-gel method.The diameter of nanowires is 40-60nm,and the length is 150-200nm.The composition,pattern and magnetic performance of the nanowires were characterized by XRD,FESEM and VSM.The rapping and ordering of the BaFe12O19 nanowires was carried out by magnetic force.The results show that the preferred direction of magnetization of BaFe12O19 is along to the nanowire direction,and the nanowires alignment is along the line of force,joint alpha and omega to chain.When magnetic field is parallel with the array of BaFe12O19 nano-chain,BaFe12O19 nanowires possess high residual magnetization（Mr）,specific magnetism（Ms） and maximum magnetic energy product（BH） m,the coercivity（Hc） is increased from 3.98×105A/m to 5.01×105A/m,the specific magnetism S⊥（ratio of Br and Hc） approaches to 0.9,all of this show that BaFe12O19 nanowires are the high density vertical magnetic recording medium.