Giant Hall effect in two-dimensional CoSi₂ granular arrays

Granular metals are essential in sensor and device applications and provide customizable electrical characteristics. We fabricated a series of nonmagnetic granular CoSi₂ thin films and investigated their transport characteristics and Hall effect. In films that are just above the metal-insulator transition, we found that the Hall coefficient is enhanced by two orders of magnitude. The reduction of the charge carriers caused by the local quantum-interference effect is ascribed to this Giant Hall effect (GHE). Transmission electron microscopy images and transport measurements show that our films form quasi-two-dimensional granular arrays. The GHE may provide useful and sensitive applications.