Utilization of a contact scanning recording tester in the study of perpendicular magnetic recording.

摘要

The perpendicular magnetic recording technology is predicted to have a physical density limit to be at least five times of that of the conventional longitudinal magnetic recording. Such potential makes the perpendicular recording one of the candidates for the yet to accomplish 1Tb/inch 2 recording density. It is also the major research and development direction of the magnetic disk data storage industry. However, since the perpendicular recording is a new technology, it brings up new challenges. The write head remanent field and overwrite modulation are two of the new issues in perpendicular recording.; This dissertation describes the, experimental studies that are used to characterize the remanent field of perpendicular write heads as well as the overwrite modulation in perpendicular recording utilizing a contact scanning recording tester. With the versatile recording ability and the high resolution imaging capability of the contact scanning recording tester, the write head remanent field and the overwrite modulation in perpendicular recording are studied microscopically. Perpendicular recording heads of different designs and perpendicular media with different magnetic properties are used in the studies. The testing results from different head and medium combinations used in the studies are presented. The physical mechanisms that are responsible for the observed write head remanent field and the overwrite modulation phenomena are discussed.; Besides the above studies, the experimental characterization of write head field gradients with a partial erasure method utilizing the contact tester system is also performed. The method shows clear improvement of the write head trailing field gradient over the side field gradients. The method is also used to compare the field gradients between different head designs.; Application of the contact tester system in other recording and imaging tests is presented in the dissertation. It describes the characterization of tape recording media and recording heads with the contact tester system, as well as the imaging of perpendicular write head erasing areas in the presence of an ambient DC field.; The contact tester system shows unique recording and imaging capabilities from the studies performed. Further developments of the system with RF frequency measurement structures are also proposed and discussed in the dissertation.