Electrical property investigations of carbon, lubricant, and alternative overcoats of magnetic discs using mercury probe

This paper describes the results on the electrical properties of carbon, lubricants, and alternative overcoats of magnetic discs using mercury probe. Our data show that resistivity of the carbon overcoat is highly dependent upon carbon composition and process condition. For DC-magnetron sputtered carbon, C:H carbon has much higher resistivity than C:H:N carbon. On the other hand, ion beam deposited carbon has higher resistivity than sputtered carbon. This effect is more pronounced for C:H:N type carbon. The DC break-down voltage of carbon overcoat is a function of film thickness. Thicker carbon has a higher break down voltage, Z-dol lubricant is nonconducting and has very low break-down voltage. Resistivity of SiN and AlN overcoats on Al and glass substrates is also reported.