The Composition and Magnetic Property of Co/Cu Alloy Microwires Prepared Using Meniscus-Confined Electrodeposition: Effect of [Co²⁺], [Cu²⁺] Concentration at the Tip of the Meniscus

Abstract

Meniscus-confined electrodeposition (MCED) is an effective and versatile technique for fabrication of alloy structures with precise localization and high controllability. Here, the fabrication of cobalt-copper (Co/Cu) alloy microwires using MCED techniques is reported. Co/Cu microwires with a wide range of compositions (Co9Cu91 to Co100Cu0) and controllable morphology were printed using the co-electrodeposition mode from a single electrolyte. We utilized multiphysics finite element simulation to investigate the influence of electrolyte evaporation and electric field on the concentration distribution of metal ions in the meniscus. The concentration of ions at the substrate interface increases linearly with decreasing humidity and increasing current density, which can be used to fine turn the alloy composition. By further analyzing the alloy composition, we found that the electrodeposition of Cu is diffusion controlled, while Co is mainly electrochemical reaction controlled, as a results of combined action of surface evaporation and reaction dynamics in the meniscus. The prepared alloy wires are polycrystalline, dense and uniform composition distribution. The coercivity and magnetic anisotropy are enhanced by increasing of the copper content in the alloy wires. The high tunability of composition make this alloy a promising material for magnetic micro/nano-electromechanical devices.

Electrodeposition of Nanostructured Co–Cu Thin Alloy Films on to Steel Substrate from an Environmentally Friendly Novel Lactate Bath under Different Operating Conditions

“…However, needle-shaped crystals, as well as larger ones with a spheroidal shape, were obtained from citrate electrolyte. Lei et al [79] deposited a Co-Cu alloy from a bath containing boric acid and saccharine. The deposition efficiency ranged between 60 and 100%, and the obtained deposits were tiny crystals oriented in all directions.…”

Micron-scale additive manufacturing of binary and ternary alloys by electrohydrodynamic redox 3D printing

“…In contrast, electrochemical AM (ECAM) techniques fabricate as-printed dense and pure metal structures from a wide range of readily available metal salt precursors [26][27][28][29][30][31] , and are thus promising candidates for the direct deposition of highperformance materials. In general, a wide range of alloys can be electroplated in thin-film form 32 and should, in principle, be accessible with small-scale ECAM as well -yet, only recently a number of binary alloys have been demonstrated: Cu-Co alloys with variable composition by meniscus confined deposition 33 , Ni-Co and Ni-Mn alloys by electroplating of locally dispensed ions (FluidFM) 34 and Cu-Ag alloys by electrohydrodynamic redox printing (EHD-RP) 35 . A general challenge in the deposition of alloys is the retardation of the more noble metal's deposition rate to avoid its preferential deposition 32 , which is typically achieved by a large surplus of the less noble metal ions 36 , by the use of surface active additives 34,36,37 , complexing agents, or deposition in diffusion limited current ranges 32 .…”

How Anionic Dopants Impact the Electrochemical Additive Manufacturing of Polypyrrole

“…32,33 On the other hand, the insufficient deposition rate hinders the applications of ECAM processing. 34 A flow-rate-controlled double-nozzle system, derived from a supply−suction apparatus, was developed for mesoscale ECAM fabrications. 35 The progress in ECAM techniques evokes the development of new strategies for manufacturing advanced PPy at high deposition rates.…”

“…In a work by Kim et al, the method allows the production of high-aspect-ratio PPy nanowires, in which the radius of wires could be minimized to 50 nm . However, the meniscus evolves unstable interactions as the diameter increases owing to insufficient surface tension, thus obstructing the fabrication of a microstructured subject. , On the other hand, the insufficient deposition rate hinders the applications of ECAM processing . A flow-rate-controlled double-nozzle system, derived from a supply–suction apparatus, was developed for mesoscale ECAM fabrications .…”