BRIEF DESCRIPTION OF THE DRAWINGS
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.
The above and other features and aspects of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a cross-sectional view of a perpendicular magnetic recording medium according to an exemplary embodiment of the present invention;
FIGS. 2A and 2B are cross-sectional views illustrating the write and read operations of the perpendicular magnetic recording medium of FIG. 1;
FIG. 3 is a cross-sectional view of a perpendicular magnetic recording medium according to another exemplary embodiment of the present invention;
FIG. 4 is a cross-sectional view of a perpendicular magnetic recording medium according to another exemplary embodiment of the present invention;
FIG. 5 is a cross-sectional view of a soft magnetic underlayer (SUL) structure that can be applied in a perpendicular magnetic recording medium, according to an exemplary embodiment of the present invention;
FIG. 6 is a graph illustrating a relationship between thickness and magnetic characteristics of an SUL formed of CoZrNb of a perpendicular magnetic recording medium;
FIG. 7A is a cross-sectional view of a soft magnetic underlayer structure that can be applied in a perpendicular magnetic recording medium, according to another exemplary embodiment of the present invention;
FIG. 7B is a graph illustrating a relationship between an applied magnetic field and the resulting magnetization of the SUL structure of FIG. 7A;
FIG. 8 illustrates SUL structure samples (a), (b), and (c) for comparing signal-to-noise ratios (SNRs) thereof;
FIGS. 9A through 9C are simulation results respectively illustrating the magnetic domain structures of the samples (a), (b), and (c) of FIG. 8; and
FIGS. 10A through 10C are simulation results respectively illustrating magnetic domain wall noises of the samples (a), (b), and (c) of FIG. 8.