Structure and magnetic properties of metastable Co–Cu solid solution nanowire arrays fabricated by electrodeposition

Abstract

Nanowire arrays of the metastable Cox Cu1–x (0.20 ≤ x ≤ 0.85) solid solution system which can not be obtained by equilibrium methods, were prepared by electrodeposition in pores of anodic aluminum oxide (AAO) template, and subsequently annealed at different temperatures. The as‐deposited samples all show single phase of fcc structure, and lattice parameters decrease with the increase of Co content and fundamentally accord with Vegard's law. The phase transition with heat treatment was investigated by X‐ray diffraction and differential thermal analysis (DTA) which further confirmed the formation of solid solution. With Co content increasing, the coercivity along nanowire axis for as‐deposited samples increases, but it decreases for the annealed samples at 700 °C. This phenomenon was explained considering the interaction of Co particles through Cu in nanowires after phase separation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Tailoring magnetic properties in arrays of pulse-electrodeposited Co nanowires: The role of Cu additive

“…It should be noted that, due to the very small amount of the Cu additive, a CoCu alloy peak and/or a Cu peak has not been detected in the XRD patterns. Furthermore, no shifts in the XRD peaks are observed, so that CoCu solid solution alloys cannot be indicated [39,40]. However, based on the recent study on CoCu NW arrays obtained by dc electrodeposition, for a small Cu content (e.g., Co 92 Cu 8 ), (110)-hcp peak in pure Co NWs disappeared and a (200)-fcc Co reflection emerged due to the addition of Cu [38].…”

Highly Efficient Direct Electrodeposition of Co−Cu Alloy Nanotubes in an Anodic Alumina Template

“…The lattice constants of the Co-Cu <111> and Co-Cu <200> directions are 0.2050 and 0.1785 nm, respectively, which are consistent with previous reports. 29,30 The other three peaks in this spectrum resulted from the diffractions of the sputtered Au film. We can roughly estimate the size of the crystallites consisting of the NTs via the Debye-Scherrer formula where K ) 0.89 is the Scherrer constant, and λ and β represent the wavelength of the X-ray and the full width at half-maximum of the diffraction peaks, respectively.…”

Formation and stabilization of single-crystalline metastable AuGe phases in Ge nanowires

“…In the bulk, metastable phases form in non-equilibrium processes, e.g., rapid cooling and crystallization from the liquid state [2], or can be stabilized in thin films by epitaxy [3][4][5][6], and via non-equilibrium growth [7][8][9][10][11][12][13]. Metastable phases in nanowires (NWs) have also been achieved by non-equilibrium synthesis [14][15][16][17][18][19][20]. Here we demonstrate a pathway to forming nanoscale metastable solids, which involves the stabilization of the liquid phase [21] and crystallization of an extremely supercooled melt.…”