Performance roughness characterization for high density magnetic recording systems

As technology moves to 40 Gb/in/sup 2/ areal densities and channel density above 3, media homogeneity and nonlinear transition interaction become crucial in defining the reliability of the recording systems. As a result, mapping and zoom-in analysis of the recording capability/performance becomes important. Two concepts are proposed in this work for performance analysis: recording performance roughness analysis and dynamic magnetic roughness analysis. The recording performance roughness analysis is based on an in-situ measurement technique of the nonlinear transition shift (NLTS). Relationship between the performance roughness and the roughness of dynamic magnetic parameters are studied. Results of experimental investigations indicate that the NLTS based performance roughness analysis can reveal more details on media's recording capability and the capability fluctuation and is an effective method for performance evaluation and failure analysis.