Mechanical property measurements of thin-film carbon overcoat on recording media towards 1 Tbit/in ²

In the pursuit of extremely high areal density recording of 1 Tbit in2, very thin protective carbon overcoats are needed, and reliable measurement of their mechanical properties is critical. Measuring mechanical properties of thin films has been challenging especially as their thicknesses have shrunk to only few nanometer thick, and one is faced with both instrument and technique limitations in extracting reliable information about such films. Two common techniques utilized for the characterization of submicron thin films are the nanoindentation and nanoscratch techniques. In this paper, shallow sub-10-nm nanoindentation and nanoscratch experiments were performed to extract the mechanical properties of reduced elastic modulus, hardness, and shear strength of a 10-nm-thick magnetic medium carbon overcoat.