Fabrication of Cobalt Nanostructured Materials by Using the Anodic Aluminum Oxide as Template

• Main Authors: Tsai, Yi-Hsuan, 蔡怡萱
• Other Authors: Pan, Fu-Ming
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/91684763772141742590

碩士 === 國立交通大學 === 材料科學與工程系所 === 97 === Due to many interesting properties of nanostructured material, studies and applications of nanomaterials have attracted much attention in recent years. How to control the size, shape and arrangement of nanostructured materials is a key issue in current research. Highly ordered cobalt nanorod arrays are successfully electrodeposited using the nanoporous anodic aluminum oxide as the template. We use two methods to increase the conductivity of the AAO template. In one method, the thickness of the barrier layer is first decreased by lowering the anodization voltage. The other method uses the unanodized aluminum as the conductive layer. The size of cobalt nanomaterial is controlled by changing the pore widening time. We can obtain various cobalt nanorods of various height by changing the electrodeposition time. Finally, the AAO template is removed by NaOH. The study shows that polycrystalline cobalt naorods are electrodeposited. The magnetic moment is related to the crystal structure. The structure of cobalt nanorod prepared with the template of smaller pore size is mainly hcp(002). The magnetic force microscopy (MFM) pattern of every cobalt nanorod is either completely bright or completely dark. The magnetic moment of the cobalt nanorod is perpendicular to the sample surface and parallel to the hcp [002] direction. On the other hand, the structure of cobalt nanorod prepared with the template of larger pore size is hcp (002) and fcc (200). The magnetic moment of the cobalt nanorod is parallel to the sample surface. The MFM pattern of every cobalt nanorod consists of one bright and one dark contrast regions.