Morphological and fractal studies of silicon nanoaggregates structures prepared by thermal activated reaction

Al-SiO2 interface has been extensively investigated in the past in both the fields of electronic components and of composite materials. The first studies showed that thermal treatment of the interface lead to the formation of small crystallizations with quite uneven distribution. We have previously revisited these crystallizations in the context of fractal growth and reported the formation of diffusion limited aggregates (DLA) or deposition diffusion aggregates (DDA) for temperature respectively higher or above the eutectic point of the Al-SiO2 reaction. We proved that these structures are made of silicon nanoaggregates. We report in this paper the correlation between real and imaginary part of the impedance and the fractal dimension of the samples as a function of their morphology. Results are compared to a model based on an equivalent electrical circuit.