Magnetic properties and preparation of Ni nanowires array by electrochemically deposited with pulse voltage

Two steps electrochemical anodizing approach was introduced to prepare the porous aluminum oxide(AAO) in sulfuric acid solution.The SEM image shows that the pore diameter with round feature is 20nm,interpore spacing is 50nm and the pore density is 4.5×1010 pores/cm2.Ordered Ni nanowires array embedded in AAO template have been fabricated by electrodepositing the Ni into the pores of AAO by pulse voltage.The results show that the preferred orientation of those nanowires with diameter of 15-20nm is crystal plane of Ni-(220).The easy magnetization axis of this system is perpendicular to the AAO membrane.When the outer magnetic field perpendicular to the membrane,the squareness is as high as 90.5% and coercivity is 63.84kA/m.