不同结构镍纳米线阵列的制备及其磁性

Fabrication and magnetic properties of nickel nanowires with different structure

采用直流电沉积在多孔有序氧化铝模板中制备了不同结构的有序镍纳米线阵列。采用SEM和TEM对所制备的镍纳米线的形貌和结构进行了表征。研究了镍纳米线不同结构对镍纳米线阵列磁性性能的影响规律．当电沉积电压为2．5V时制备的镍纳米线为多晶结构；电沉积电压4V时，镍纳米线为沿[220]择优取向的单晶结构；电沉积电压＞5V时，择优取向由[220]转为[111]方向．磁滞回线结果表明，单晶镍纳米线阵列与多晶纳米线阵列相比具有更高的矩形度，沿[111]择优取向的单晶纳米线相比沿[220]取向的单晶镍纳米线具有更大的矩形度，表现出显著的磁各向异性。

Nickel nanowires with different structure were prepared directly by electrodeposition in anodic alumina membrane （AAM）. The structure and topography of the nanowires were characterized by SEM and TEM. Effect of nanowires structure to the magnetic properties of the nickel nanowires was studied. It was shown that the nickel nanowires were poly-crystalline when the deposition voltages were 2.5V. The nickel nanowires changed to single crystal with a preferred orientation along [220] when the deposition voltages were 4V. The preferred orientation transformed from [220] to [111] with deposition voltages were larger than 5V. The single-crystalline Ni nanowires exhibited excellent magnetic properties （large squareness and large coercivity） to compare with poly-crystalline Ni nanowires. Single-crystalline Ni nanowires with a preferred orientation along [111] had a larger squareness than that with [220] orientation.