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Hi Boer,
Thanks for responding.
Have you got an explanation for the difference in frequencies for the two
metals? e.g. why are they different if the electrode are of the same size?
Also the paper mentions that other metal were tested and they also showed to
have different frequencies. Have you got this data to hand?
Wayne
"boer" wrote in message
news:7e6dnRj8ZOTHGW_cRVn-1Q@adelphia.com...
> WayneL wrote:
>> Hi
>>
>> I have read a paper on Fabrication of highly ordered metallic nanowire
>> arrays by electrodeposition by Yin a Brown University, US. See link for
>> a copy of the paper.
>> http://optonano.engin.brown.edu/Publications/APL01039.pdf
>>
>> This paper discusses, among other things, the deposition of Bi and Ni to
>> produce nanowires.
>>
>> Yin grew nickel and bismuth nano-wire using AC electrodeposition for
>> applications of high density recording devices and sensors. Yin used an
>> AAO (self-ordered anodised aluminium oxide) film as the cathode and a
>> graphite bar as the anode. He states that electrodeposition of metal
>> into the porous alumina film directly following anodisation can take
>> place only under AC conditions. Producing either Bi or Ni nano-wires
>> required different conditions.
>> Yin also found that the frequency range used also affected the results
>> produced. Another point worth noting is that high quality deposition of
>> Ni could be obtained with AC frequencies from 10 to 750 Hz and for Bi the
>> optimum frequency range was between 10 and 100 Hz. He commented that
>> this was probably due to the double layer. However, if the double layer
>> is the main factor dictating the frequency response then surely the
>> frequency he stated would be a function of the electrode size? Thus his
>> figure are arbitrary as they do not have any dimensional data. And if he
>> did use the same size electrodes for both Bi and Ni deposition why would
>> the frequencies be different? Surely the double layer capacitance is the
>> same for both metals or am I missing something here or is the double
>> layer capacitance a function of the metal's atomic number? One thing
>> that is obvious is that Bi(83) is significantly heavier than Ni (28).
>>
>> Could somebody possible help clear this up for me.
>>
>> Cheers
>>
>> Wayne
>>
>>
> The use of AC voltage is to overcome the barrier layer at the bottom of
> the pores during the fabrication process, as stated in the paper. The
> thinness/thickness of this non-porous layer presents a difficulty in DC
> plating of the nanopores. This is *not* the double layer capacitance per
> your post. The paper does discuss barrier thinning voltages compared to
> older methods using dilute phosphoric acid etching to thin this physical
> barrier layer. Yes, our lab did indeed find differences in AC plating
> frequencies of nanopores dependent on the metal to be deposited.
>
> boer
>
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