Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : March 07, 2022 - March 08, 2022
Heat-Assisted Magnetic Recording (HAMR) is expected as one of the future high density recording technologies. When the magnetic film is heated at Curie temperature (Tc) around 600K (357 degree Celsius) for CoPt system with a near-field transducer (NFT), carbon overcoat film (COC) and lubricant film are also heated. Therefore, thermal life estimation of these thin films is strongly requested. We have developed new measurement systems based on surface-enhanced Raman spectroscopy (SERS). Our measurement tool composed of a transmission-type plasmonic sensor (TPS) has ultra-high sensitivity of 370,000 times greater than that of the normal Raman spectroscopy in magnitude to measure chemical structures and film temperature. Heating temperature can be measured by intensity ratio of anti-Stokes to Stokes peaks in SERS spectra. We report the life estimation of COC and lube film from Raman spectral change by heating emulation using plasmonic sensor array (PSA) with 2.5” disk drive with 10,500 rpm. As a result, no degradation was observed on COC and lubricant film after laser heating for typical HAMR condition at 350 degree Celsius.
