Electrical and Magnetic Properties of Nanocystalline Diamond Films

The magneto resistive effect in nanocystalline diamond films was investigated at room temperature. The nanocystalline diamond films on silicon were deposited by hot filament chemical vapor deposition. The experimental results showed that a striking magneto resistive effect in p-type doped nanocystalline diamond films was observed. The relative changes in the resistivity of the films were about 0.3 at room temperature under the magnetic field of 5T, and increased with decreasing the geometrical size of the devices. It was found that the magneto resistive effect in the nanocystalline diamond films was less than that of epitaxial diamond films. This was ascribed to a large number of grain boundaries. The results are discussed in detail.