Theoretical and Experimental Prospects of Perpendicular Magnetic Recording

Abstract

--In magnetic recording, information data is written by the perpendicular magnetization component even in a longitudinally oriented recording medium, especially when it consists of non-interacting fine magnetic particles. The future prospect of magnetic recording has been theoretically investigated using a computer simulation from the viewpoint of media having both higher recording resolution and higher output. Recording bit density over 500 kFCI accompanied with higher surface flux density has been confirmed in perpendicular magnetic recording not only by experiments but also by computer simulations. Novel techniques on head-to-medium interfaces and very narrow track single-pole heads for a hard disk magnetic recording system have been also discussed to materialize ultra-high density perpendicular magnetic recording.

Self-assembly of shape-controlled nanocrystals and their in-situ thermodynamic properties

“…In ultra-compact information storage, for example, the size of the domain determines the limit of storage density while the sharpness of the domain boundaries is closely related to the media noise. This issue is critically important in the 300 Gbit/in 2 information storage density predicted for the 21st century [13,14]. The noise reduction can be achieved by the segregation of a non-magnetic phase at the grain boundaries, thus, the media are composed of at least two materials.…”

A Challenge to Terabit Perpendicular Spinic Storage

“…If a storage medium is an assembly of particles of several tens nanometer in diameter, a bit may be written in several ten-thousands of particles in the current diskdrive of 400 Mb/inch 2 but it will be written in several thousands of particles in the next disk-drives of 2 Gb/inch 2 In contrast, we have already confinned many times by [11], and moreover, several hundreds of particles in the experiments [4,6,13] and also by computer simulations [4, future ones of 10 Gb/inch 2 [12]. 14] that an extremely high bit density recording exceeding 25 kFRPM or 600 kFRPI is achievable through perpendicular magnetic recording.…”

Domain structures and temperature-dependent spin reorientation transitions in c-axis oriented Co–Cr thin films

“…This approach, however, will collapse when the superparamagnetic and/or thermal decay limit is reached. As an alternative, based on the analysis of the demagnetization mechanisms, Iwasaki and Takemura 1 suggested the possibility of perpendicular magnetic recording ͑PMR͒, and computer simulation, 2 predict that an areal density of more than 300 Gbit/in. 2 can be achieved for the PMR mode.…”