Measurement of Down-track Correlation for Perpendicular Magnetic Media with Various Exchange Coupling

In this work intergranular exchange coupling was focused to be the major parameter to govern the cluster size and thus track edge noise and resolution. CoPtCr-SiO₂/SUL perpendicular media with various SiO₂ contents from 9.2 at% to 12.7 at% were used for this experiment. The different intergranular exchange couplings of these media, and therefore, different slope parameters a from 2.89 to 3.58 were considered as a major parameter here. A single-pole head whose track width of 180 nm without shields was employed for writing. Track width of the reader was 140 nm.