Fabrication Of Multi-Componentand Multi-Phase Alloy Magneticnanowires By Electrochemicaldeposition

In recent years,perpendicular magnetic recording medium has been widely applied as the main information media.Magnetic nanowires become a potential ultra high density perpendicular magnetic recording medium for its high shape anisotropy.In the future,magnetic nanowires have broad application prospect.In this paper,Fe-Co single-phase and Sm-Co/Fe-Co dual-phase magnetic nanowire arrays were prepared by electrochemical deposition with AAO templates firstly.In view of the current vacancies in the research of multielement rare earth transition metal alloy magnetic nanowires,the Tb-Fe-Co ternary alloy nanowire arrays were successfully prepared by adding the heavy rare earth element Tb³⁺into the Fe-Co deposition solution.Furthermore,the Sm-Co/Tb-Fe-Co multielement rare earth alloy magnetic nanowire arrays were prepared by alternately depositing in Tb-Fe-Co solution and Sm-Co solution.Finally,the composition,phase,morphology,crystal structure and magnetic properties of nanowires were characterized and analyzed by EDS,XRD,SEM,TEM and VSM.The results are as follows:1.The XRD shows that the Fe-Co alloy is crystal structure before and after annealing.Sm-Co alloy is amorphous structure before annealing and Sm₂Co₁₇7 phase is formed after annealing.Tb-Fe-Co nanowires and Sm-Co/Tb-Fe-Co nanowires are both composed of FeCo crystal phase and other amorphous phases.In addition,the amorphous phase crystallizes after annealed at 600?for 3 h.The annealed Tb-Fe-Co nanowires are composed of FeCo phase,Fe₂Tb phase and Co₂Tb phase,and the annealed Sm-Co/Tb-Fe-Co nanowires are composed of FeCo phase,Fe₂Tb phase,Co₂Tb phase and Sm₂Co₁₇7 phase.2.The SEM photos exhibit that the nanowires have smooth rod like structure,highly ordered arrangement and good filling degree.The average diameter of nanowires is about70 nm,and the length diameter ratio can reach 178.The HRTEM diagrams show the nanowires have higher crystallinity and obvious crystal lattice stripes after annealed at600?for 3 h.3.The magnetic properties of Tb-Fe-Co and Sm-Co/Tb-Fe-Co nanowires with different Tb³⁺concentrations are measured.The results show that the magnetic properties of Tb-Fe-Co ternary alloy nanowires are better than those of Fe-Co binary alloy nanowires;the magnetic properties of Sm-Co/Tb-Fe-Co multielement and multiphase nanowire arrays are better than Sm-Co/Fe-Co dual phase alloy nanowires.The best comprehensive magnetic properties of annealed Tb-Fe-Co nanowires and Sm-Co/Tb-Fe-Co nanowires are obtained when the Tb³⁺concentrations are 0.10 mol/L and 0.15 mol/L,respectively.The coercivity of Tb-Fe-Co nanowires parallel to the easy magnetization axis is 3400.12 Oe,and the remanence ratio is 0.89.Moreover,the coercivity of Sm-Co/Tb-Fe-Co nanowires parallel to the easy magnetization axis is 3875.76 Oe,and the remanence ratio is 0.92.