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Nanoscale pit patterns were formed on a polycarbonate substrate surface, which is commonly used for compact disks, by direct nanoprinting. Pit patterns with 100, 70, and 63 nm pitches were imprinted on the disk surface using a SiC mold with a nanostructure projection pattern. These pitches correspond to the the storage densities of 75, 150, and 185 Gbit/in 2 . We evaluated the mold-holding temperature and press-pressure dependence of the pit depth. We also evaluated the press-time dependence. With a relatively low press-pressure of 1.3 kg/mm 2 at room temperature, a 100-nm-pitch pit pattern with a pit depth of over 40 nm was fabricated using a mold with a projection height of 60 nm.

To find a way to control the compositional change in Bi-substituted garnet during sputtering, we studied the effects of controlling the cathode magnetic field. The magnetic-field-controlled rf magnetron sputtering method that we developed can create a garnet film whose composition is the same as that of the sputtering target. When we deposited a film of Bi-substituted Dy iron garnet–ferrite (Bi2DyFe4GaO12) by this method, there was no compositional change between the target and the film even after a long sputtering process. Therefore, this sputtering method is effective at suppressing compositional change during the film formation process.

Hall effect measurement has been used to detect the perpendicular and in-plane magnetization components simultaneously in a [Co/Pd]n multilayer thin film with strong magnetic anisotropy along the direction perpendicular to the film plane. The angle between the driving current direction and the in-plane projection of the applied magnetic field was varied to investigate the contribution of in-plane magnetization component to the measured Hall voltage. Hall voltage under the canted magnetic field revealed that the output is the superposition of the anomalous Hall effect (AHE) due to the perpendicular component of magnetization and the planar Hall effect (PHE) due to the in-plane magnetization component. Odd symmetry characteristics of AHE and even symmetry characteristics of PHE with respect to applied field have been applied to extract the Hall voltage contributed by the two different magnetization components from their combined characteristic. Anomalous Hall voltage from the perpendicular magnetization component exhibited an irreversible hysteresis loop while that from the in-plane magnetization component was found almost reversible with respect to applied magnetic field. The method was effective to evaluate the in-plane component of magnetization in an ultrathin film under the canted magnetic field.

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