  Granular metals offer tailorable electronic properties and play crucial roles
in device and sensor applications. We have fabricated a series of nonmagnetic
granular CoSi2 thin films and studied the Hall effect and transport properties.
We observed a two orders of magnitude enhancement in the Hall coefficient in
films fall slightly above the metal-insulator transition. This giant Hall
effect (GHE) is ascribed to the local quantum-interference effect induced
reduction of the charge carriers. Transmission electron microscopy images and
transport properties indicate that our films form two dimensional granular
arrays. The GHE may provide useful and sensitive applications.
