Magnetic properties of Co–Pt alloy nanowire arrays in ina anodic alumina templates

bled re of along llel to ature while ature polar with . The de of Microstructure and magnetic properties of ferromagnetic Co9Pt nanowire arrays electrodeposited into self-assem anodic alumina templates have been investigated. X-ray diffraction shows that as-prepared Co–Pt nanowires a FCC polycrystalline structure. The nanowires with diameter do80nm are mainly of (1 1 1) preferred orientation the wire axis. For a specific diameter, the coercivity and the remanent ratio with the external magnetic field para the nanowire axis, i.e., the parallel geometry, are larger than those of the perpendicular geometry. With temper increasing from 90 to 600K, above two physical quantities in the perpendicular geometry decrease monotonically, those of the parallel geometry change little. The dependence of the coercivity and the remanent ratio on temper and the nanowire diameter can be explained after the shape and the magnetocrystalline anisotropies, and the di magnetic interaction are considered. For the parallel and perpendicular geometries, the coercivity decreases increasing diameter d as a linear scale of 1=d and approaches each other in the two geometries for large d degradation of coercivity in Co–Pt nanowires with increasing diameter is suggested to come from the curling mo magnetization reversal process. r 2005 Elsevier B.V. All rights reserved.