2023 年 47 巻 1 号 p. 1-14
In this work we examine grain arrangement and medium structure, temperature profile during writing, adjacent track interference, information stability during 10 years of archiving, information stability in a high Curie temperature (HC) layer during writing in a low Curie temperature (LC) layer, and writing sensitivity on 4 Tbpsi shingled heat-assisted magnetic recording (HAMR) with a bit aspect ratio of 1.5 and 2 Tbpsi/layer (total density of 4 Tbpsi) three-dimensional (3D) HAMR with bit aspect ratios of 1.0 and 2.0. A small bit aspect ratio is preferable in 3D HAMR. The grain aspect ratios for both HAMR and 3D HAMR may be too large when it comes to manufacturing the recording layer. The low Curie temperature of the LC layer may be disadvantageous with respect to the writing property. The readout field is small for both the LC and HC layers in 3D HAMR. The writing sensitivity for HAMR is worse than that for 3D HAMR because the statistical factor is affected by the readout grain number and erasure-after-write is affected by the grain column number. Although both HAMR and 3D HAMR have disadvantages, the poor writing sensitivity in HAMR is a serious problem.
