title: Magnetization reversal and magnetic anisotropy in ordered CoNiP nanowire arrays: effects of wire diameter.
abstract: Ordered CoNiP nanowires with the same length of 4 µm and varying diameters (d = 100 nm-600 nm) were fabricated by electrodeposition of CoNiP onto polycarbonate templates. X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy confirmed the quality of the fabricated nanowires. Magnetic measurements and theoretical analysis revealed that the magnetization reversal and magnetic anisotropy were significantly influenced by varying of the diameters of the nanowires. There existed a critical wire diameter (dc ≈ 276 nm), below which the magnetization reversal occurred via a coherent rotation mode, and above which the magnetization reversal occurred via a curling rotation mode. The easy axis of the magnetization tended to change in direction from parallel to perpendicular with respect to the wire axis as the wire diameter exceeded dc ≈ 276 nm. With increasing wire diameter, the coercive field (Hc) and the remanent to saturation magnetization ratio (Mr/Ms) were also found to rapidly decrease in the range d = 100-400 nm and gradually decrease for d > 400 nm.
authors.affiliation: Faculty of Engineering Physics and Nanotechnology, VNU University of Engineering Technology, Vietnam National University, 144 Xuan Thuy, Cau Giay, Hanoi, Vietnam. hilvt22380@yahoo.com.|Faculty of Basic Science, Hanoi Industrial College for Textile, Garment and Fashion Le Chi, Gia Lam, Hanoi, Vietnam. hilvt22380@yahoo.com.
authors.forename: Luu
authors.initials: L
authors.lastname: Van Thiem
authors.affiliation: Faculty of Physics, VNU University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam. letuantu@hus.edu.vn.
authors.forename: Le Tuan
authors.initials: le T
authors.lastname: Tu
authors.affiliation: Department of Physics, University of South Florida, Tampa, FL 33620, USA. phanm@usf.edu.
authors.forename: Manh-Huong
authors.initials: MH
authors.lastname: Phan