Probing the conducting paths in a metal - insulator composite by conducting atomic force microscopy

We have imaged the conducting paths in a metal - insulator composite , with x ranging from 0.24 to 0.576 by conducting atomic force microscopy (AFM). The surface morphology and the electric current between the tip and sample have been obtained simultaneously on the nanometre scale. Measurable changes of current image have been observed for x below and above the percolation threshold . Our observations imply the importance of tunnelling for all samples. The high spatial resolution of AFM combined with a conducting tip provides new insight into electron transport behaviour in metal - insulator composites at the nanometre