An ac impedance study of dendritic silver three-dimensional electrodeposits
The ac impedance behaviour of electrochemically grown dendritic Ag three-dimensional electrodeposits grown from aqueous Ag<sub>+</sub> ion containing solutions has been studied in the blocking regime covering the 1 ⩽ f ⩽ 10<sub>4</sub> Hz frequency range (ω = 2πf). These depo...
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| Autores principales: | , , , , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
1993
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/118957 |
| Aporte de: |
| Sumario: | The ac impedance behaviour of electrochemically grown dendritic Ag three-dimensional electrodeposits grown from aqueous Ag<sub>+</sub> ion containing solutions has been studied in the blocking regime covering the 1 ⩽ f ⩽ 10<sub>4</sub> Hz frequency range (ω = 2πf). These deposits exhibit fractal surface and non fractal mass (volume) characteristics. Impedance data displayed as log Z″ vs. log ω plots show two linear portions with different frequency dispersion exponents <α > = 0.95 ± 0.03 and <α > = 0.67 ± 0.05, respectively. The crossover frequency, ω<sub>λ</sub>, as determined from those plots, mainly depends on the electrolyte resistivity and, to a minor extent, on the Ag<sub>+</sub> ion electrodeposition charge. For ω > ω<sub>λ</sub>, the surface fractal dimension derived from the reciprocal relationship, D<sub>s</sub> = (1/α) + 1, is D<sub>s</sub> = 2.45 ± 0.1. This figure agrees with that obtained from the log (area) vs. log (volume) plots. |
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