Journal of The Electrochemical Society, 152 ͑1͒ A37-A41 ͑2005͒
A41
extinction coefficient as well as an increase of ca. 10% in thickness.
The comparison of experimental data with simulated ⌿-⌬ curves for
different mechanisms of film conversion indicates that electroreduc-
tion of MnO2 to Mn͑III͒ species is consistent with a gradual increase
of the thickness of an outer Mn͑III͒ oxide layer at the expense of the
MnO2 inner layer, i.e., the Mn(IV) → Mn(III) conversion takes
place from the oxide/electrolyte interface inwards.
Acknowledgments
Financial support from the Consejo Nacional de Investigaciones
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Cientıficas y Tecnicas of Argentina ͑CONICET͒, the Agencia Cor-
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doba Ciencia S.E., the Agencia Nacional de Promocion Cientıfica y
Tecnologica ͑ANPCyT͒, the Secretarıa de Ciencia y Tecnologıa
͑SECYT-UNC͒, and the Consejo de Investigaciones Cientıficas y
Tecnologicas ͑CICYT-UNSE͒ is gratefully acknowledged.
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Conclusions
The optical response during the anodic growth of manganese
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