New Insights in MagnetoElectroChemistry

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New Insights in MagnetoElectroChemistry

• Usefulness of high magnetic fields
• J.-P. CHOPART DTI REIMS
• M. UHLEMANN IFW DRESDEN
• F. DEBRAY GHMFL GRENOBLE

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Electrode
d
Electrolytic current lines
Electrolyte
Magnetic Forces
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1
B
2
I lim experimental g . I lim theoretical
0,1 lt g lt 0,5
Aogakis experimental cell R. Aogaki, K. Fueki,
T. Mukaibo, Denki Kagaku 43 (1975), 504-508R.
Aogaki, K. Fueki, T. Mukaibo, Denki Kagaku 43
(1975), 509-514
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Experimental setup for electrochemical MHD
measurements
Electrochemical cell
CE
REF
WE
Potentiostat
Electromagnet
(
Hall probe



B0
Power supply
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O. Aaboubi, J. Electrochem. Soc. 1991
N. Leventis, M. Chen, X. Gao, M. Canalas, P.
Zhang, J. Phys. Chem. B 1998
P. Fricoteaux, J. Phys. Chem. B 2004
Limited current Magnetic field relationships
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Limited current density vs. magnetic field for
different Cu2-concentrations, vertical
electrode and downward oriented vertical magnetic
field, dB/dt 10mT/s upward, dB/dt50mT/s
backward
M. Uhlemann, A. Krause, K. Msellak, J.-P.
Chopart, J. Electrochem. Soc., in press
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Limited current density vs. B1/3c4/3 for
different alignments of the magnetic field
M. Uhlemann, A. Krause, K. Msellak, J.-P.
Chopart, J. Electrochem. Soc., in press
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Limited current density vs. magnetic field for
different Cu2-concentrations, horizontal
electrode, faced downward and upward oriented
vertical magnetic field, dB/dt 10mT/s
upward, dB/dt50mT/s backward
M. Uhlemann, A. Krause, K. Msellak, J.-P.
Chopart, J. Electrochem. Soc., in press
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Limited current density vs. magnetic field for
different Cu2-concentrations, horizontal
electrode, faced upward and downward vertical
magnetic field, dB/dt 10mT/s upward,
dB/dt50mT/s backward
M. Uhlemann, A. Krause, K. Msellak, J.-P.
Chopart, J. Electrochem. Soc., in press
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I. Mogi Physica B (216) 1996
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Ni-Fe codeposit B 0 T, vertical copper electrode
Fe 58
Fe 35
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Ni-Fe codeposit B 13 T. Vertical copper
electrode
Fe 72
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Cu electrodeposited onto oxidized Ti . E - 400
mV / Cu.
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Blanc
blanc
Size / µm
Number of crystallites / (150 x 120 ) µm²
Copper crystallites onto oxydized titanium.
Overpotential -400 mV
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Current / mA
Time / s
Transient curves for copper electrogermination.
Overpotential -200 mV. Vertical oxydized Ti
electrode.Vertical magnetic field
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(No Transcript)
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Nucleation of copper onto oxidized Ti . E - 200
mV / Cu. Without and with high magnetic field (13
T) superimposed
along the electrode, the tangential field EH
103 - 104 V/m
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CONCLUSIONS

• For electrochemical systems, high magnetic fields
• allow to discriminate the B convective effects
  (gravitationnal effects can be disregarded)
• Can modify the electrochemical reactions in a
  very compact diffusion layer (new electrochemical
  process)
• Change the structureand the texture of
  electrodeposited metal and alloys (new surface
  properties for catalytic or anticorrosion
  properties)
• Create an anisotropy on electrode