Figure 1.
Schematic of the structure and desired magnetic properties (not to scale). The black arrows (binary “1″) and red arrows (binary “0″) denote the two possible magnetic states in each stack. Above the columns lies the binary representation and color coding for the eight possible magnetic states.
Figure 2.
ML-3D magnetic media composition.
Figure 3.
ML-3D BPM media fabrication process.
(a) Sputter-deposition of the triple-stack ML-3D magnetic media composition (b) Spin-coat and bake HSQ (c) E-beam lithography (expose and develop patterns) (d) ICP etching of the naturally oxidized Ti layer (e) Ar-ion milling of the remaining composition to form the triple-stack ML-3D BPM.
Figure 4.
A graph revealing three magnetically-decoupled recording layers for the fabricated ML-3D media.
Figure 5.
The sequence of magnetic fields applied to the triple-stack ML-3D media. The transitional external fields required to achieve the desired magnetic state were given 5 time units while 20 time units were designated for the final magnetic field.
Figure 6.
The simultaneous Kerr rotation produced by the ML-3D media as a result of the externally applied magnetic fields. The binary representation for each level along with its color coding are listed above each of the eight magnetic states.
Figure 7.
AFM image of the triple-stack ML-3D BPM.
Figure 8.
MFM image of the triple-stack ML-3D BPM.
The MFM image corresponds directly to the nanopillars shown in the Figure 7.
Figure 9.
A schematic highlighting the various magnetic states of the nanopillars shown in Figure 7.
Figure 10.
Quantification of ML MFM signals.
AFM/MFM section line analysis of the row of nanopillars located between the black arrows in Figure 8. The colored squares represent the different magnetic states as shown in Figure 1. The inset is a cropped section of the MFM image, taken between the two black arrows.
Figure 11.
Quantification of ML MFM signals.
AFM/MFM section line analysis of the row of nanopillars located between the red arrows in Figure 8. The color boxes represent the different magnetic states as shown in Figure 1. The inset is a cropped section of the MFM image, taken between the two red arrows.