R&D: Control of Head Smear Generation by Diamond-like Carbon Films

Microsystem Technologies has published an article written by Hiroshi Tani, Kansai, Renguo Lu, Shinji Koganezawa, and Norio Tagawa, Kansai University, Suita-shi, Osaka, Japan.

Abstract: “The formation of head smears in heat-assisted magnetic recording is a significant problem that must be addressed to ensure the reliability of the head-disk interface. In this study, we investigated the dependence of the electric field on the hydrocarbon smear generated by the diamond-like carbon (DLC) overcoat between a magnetic disk and a Si wafer used as a counter surface. We found that the electric field controlled the amount of hydrocarbon smear generated by the heated magnetic disks. A positive electric field extracted hydrocarbon ions from the thermal plasma toward the Si wafer, whereas a negative field attracted the hydrocarbon ions to the DLC surface. As a result, a positive electric field between the disk and the Si wafer increased the amount of smear, but a negative field reduced it. Therefore, when the laser irradiation in heat-assisted magnetic recording heats the DLC overcoat, the electric field between the slider and disk controls the smear generation.“