Correlation between structure and magnetic properties in CoxFe100−x nanowires: the roles of composition and wire diameter. (15th April 2015)

• Record Type: Journal Article
• Authors: Bran, C; Palmero, E M; Li, Zi-An; del Real, R P; Spasova, M; Farle, M; Vázquez, M
• Is Part Of: Journal of physics. Volume 48:Number 14(2015)
• Page Start: 6906
• Publication Date: 2015-04-15
• Subjects: Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/48/14/145304
• Languages: English
• ISSNs: 0022-3727

Abstract

<abstract> <title>Abstract</title> <p>The structural and magnetic characteristics of Co_{<italic>x</italic>}Fe_{100−<italic>x</italic>} (0 ≤ <italic>x</italic> ≤ 100) cylindrical nanowire arrays are investigated for two series of nanowires with diameters of 20 and 40 nm, respectively. The crystalline structure evolves with Co content from <italic>bcc</italic> Fe through a mixed <italic>bcc–fcc</italic> phase to a final polycrystalline <italic>fcc</italic> or <italic>hcp</italic> phase for 40 and 20 nm diameter Co nanowires, respectively. A monocrystalline structure is found only in a few nanowires with a 40 nm diameter.</p> <p>The magnetic characterization under axial magnetic field reveals an increase in coercivity and remanence for increasing Co content as the crystalline structure evolves from <italic>bcc</italic> Fe to <italic>fcc</italic> Co. These parameters decrease when <italic>hcp</italic> Co with a stronger magnetocrystalline anisotropy and nearly perpendicular '<italic>c'</italic> axis is formed. Overall higher values are observed in nanowires when the nanowire diameter decreases from 40 to 20 nm.</p> <p>An increase of the total magnetic anisotropy energy density is found with decreasing temperature, especially for Co wires where the strong magnetocrystalline anisotropy plays the most significant role.</p> </abstract>