copper/cobalt nanowires

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electrochemical synthesis of multilayer nanowires

Transcript of copper/cobalt nanowires

Electrochemical Synthesis of Co/Cu NanowiresElectrochemical Synthesis of Co/Cu Nanowires

GMR EFFECT

• Giant magnetoresistance (GMR) propertythe material electrical resistance whenthe material electrical resistance whenintroduced.

• This giant magnetoresistance effectelements are layered with nonmagneticcopper.

GMR EFFECT

property is described as a change inwhen an external magnetic field iswhen an external magnetic field is

effect is observed when ferromagneticnonmagnetic elements like chromium or

CIP & CPP

• CIP-GMR is limited by the layersmall, comparable to the electronsmall, comparable to the electronGMR.

• CPP-GMR is limited by anotherelectron spin diffusion length, whichelectron mean free path.

• CPP-GMR is governed by a larger• CPP-GMR is governed by a largeryield a larger resistance drop comparedby the small electron mean free path

CIP & CPP - GMR

layer thickness, which has to be verymean free path in order to exhibitmean free path in order to exhibit

another characteristic length called thewhich is several times larger than the

larger electron travel length, it wouldlarger electron travel length, it wouldcompared to the CIP-GMR that is limited

path.

Experimental

• Experimental Setup • ChronoamperometryCobalt reduction

Copper reduction potential

Experimental

Chronoamperometry/ Pulse PlatingCobalt reduction potential -1.3V for 35 s

Copper reduction potential -0.8 V for 15 s

• Platinum wire was used as the anode (or counter electrode). • Saturated Ag/AgCl electrode functioned as the potential reference. • Membrane is not conductive by nature it was coated with silver solution on one side for electrical contact.• Main electrolyte for Co/Cu nanowire deposition was composed of CoSO

and Boric acid (0.4 M). • Electrolyte was set to a pH of 2.8 using Sulphuric acid (0.5 M).• Pulsed potential plating was carried out with a computer controlled • Pulsed potential plating was carried out with a computer controlled

Platinum wire was used as the anode (or counter electrode). functioned as the potential reference.

Membrane is not conductive by nature it was coated with silver solution on one side for electrical contact.Main electrolyte for Co/Cu nanowire deposition was composed of CoSO4.7H2O (1 M), CuSO4.5H2O (0.015 M),

acid (0.5 M).Pulsed potential plating was carried out with a computer controlled Gamry Reference 600 Potentiostat. Pulsed potential plating was carried out with a computer controlled Gamry Reference 600 Potentiostat.

Results

• To check the morphology of the fabricated was done.

• To check concentration of copper and cobalt EDS was done.• To check concentration of copper and cobalt EDS was done.

• For magnetic measurements, Vibrating Sample Magnetometer was done.

Results

To check the morphology of the fabricated unetched Co/Cu nanowires SEM

To check concentration of copper and cobalt EDS was done.To check concentration of copper and cobalt EDS was done.

For magnetic measurements, Vibrating Sample Magnetometer was done.

Applications

• Manufactured materials that showmagnetic recording and magnetic field

• These magnetic materials are good candidates• These magnetic materials are good candidatesaudio-video tape heads, magnetometers,

Applications

GMR are used for perpendicularfield sensors.

candidates for computer disk drives,candidates for computer disk drives,magnetometers, compass systems, etc

Conclusion

• SEM images & EDS data clearlynanowires with less copper concentrationpores of the template.pores of the template.

• VSM data clearly shows low coercivitythese nanowires are soft magnetic materials

Conclusion

clearly show the presence of Co/Cuconcentration at the pH value 2.8 within the

coercivity Of Co/Cu nanowires. Thereforematerials.

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