The Ni, Fe, Co and Cu single and multilayer nanowire arrays to make perpendicular magnetic recording media were fabricated with nanoporous anodic aluminum oxide (AAO) templates from Watt solution and additives by the ...The Ni, Fe, Co and Cu single and multilayer nanowire arrays to make perpendicular magnetic recording media were fabricated with nanoporous anodic aluminum oxide (AAO) templates from Watt solution and additives by the DC electrodeposition. The results show that the diameters of Ni, Fe, Co and Cu single and multilayer nanowires in AAO templates are 40-80 nm and the lengths are about 30 μm with the aspect ratio of 350-750. The magnetic properties of the prepared nanowires are different under different electrodepositing conditions. The remanences (Br) of Ni/Cu/Fe multilayer nanowires are lower than those of others multilayer nanowires, and coercivity (Hc) of Ni/Cu/Fe multilayer nanowires are lower than those of others multilayer nanowires. These are compatible with the required conditions of high density magnetic media devices that should have the low coercivity to easily success magnetization and high remanence to keep magnetization after removal of magnetic field.展开更多
The X-ray low angle reflectivity measurement is used to investigate single and bilayer films to determine the parameters of nanometer-scale structures,three effectual methods are presented by using X-ray reflectivity ...The X-ray low angle reflectivity measurement is used to investigate single and bilayer films to determine the parameters of nanometer-scale structures,three effectual methods are presented by using X-ray reflectivity analysis to provide an accurate estimation of the nanometer film structures. The parameters of tungsten (W) single layer, such as the material density, interface roughness and deposition rate, were obtained easily and speedily. The base metal layer was introduced to measure the profiles of single low Z material film. A 0.3 nm chromium (Cr) film was also studied by low angle reflectivity analysis.展开更多
文摘为了减少Pt催化剂在燃料电池催化过程中的使用量、增加其催化活性,选择储量丰富、成本低廉的过渡金属Ni与Pt复合,通过交替改变电沉积过程中的沉积电压,在多孔阳极氧化铝(porous anodic alumina,PAA)模板内制备NiPt/Pt多层纳米线阵列。利用扫描电子显微镜(scanning electron microscope,SEM)、透射电子显微镜(transmission electron microscope,TEM)和X射线衍射(X-ray diffraction,XRD)仪等对样品的形貌及结构进行剖析,用电化学工作站对其电催化甲醇、甲酸的性能进行研究。结果表明,NiPt/Pt多层纳米线阵列中,Pt片段和NiPt片段呈周期性排布,催化甲醇和甲酸时最大氧化电流分别为50.2 mA/cm^(2)和102.0 mA/cm^(2),比单质Pt纳米线展现出更强的催化活性,这种增强的催化活性可能源于多层结构导致的较多Pt催化活性位点及Ni、Pt金属间的协同催化作用。
文摘The Ni, Fe, Co and Cu single and multilayer nanowire arrays to make perpendicular magnetic recording media were fabricated with nanoporous anodic aluminum oxide (AAO) templates from Watt solution and additives by the DC electrodeposition. The results show that the diameters of Ni, Fe, Co and Cu single and multilayer nanowires in AAO templates are 40-80 nm and the lengths are about 30 μm with the aspect ratio of 350-750. The magnetic properties of the prepared nanowires are different under different electrodepositing conditions. The remanences (Br) of Ni/Cu/Fe multilayer nanowires are lower than those of others multilayer nanowires, and coercivity (Hc) of Ni/Cu/Fe multilayer nanowires are lower than those of others multilayer nanowires. These are compatible with the required conditions of high density magnetic media devices that should have the low coercivity to easily success magnetization and high remanence to keep magnetization after removal of magnetic field.
基金This work was supported by the National Natural Science Foun-dation of China(10435050,60378021)the National 863-804Sustentation Fund(2006AA12Z139)+2 种基金the Program for New Cen-tury Excellent Talents in University(NCET-04-037)the RoyalSociety,London(NC/China/16660)Tongji University scien-tific fund.
文摘The X-ray low angle reflectivity measurement is used to investigate single and bilayer films to determine the parameters of nanometer-scale structures,three effectual methods are presented by using X-ray reflectivity analysis to provide an accurate estimation of the nanometer film structures. The parameters of tungsten (W) single layer, such as the material density, interface roughness and deposition rate, were obtained easily and speedily. The base metal layer was introduced to measure the profiles of single low Z material film. A 0.3 nm chromium (Cr) film was also studied by low angle reflectivity analysis.
