Quantum limit of magnetic recording density

2001 ◽  
Vol 79 (10) ◽  
pp. 1501-1503 ◽  
Author(s):  
G. A. Held ◽  
G. Grinstein
Keyword(s):  
Magnetic Recording ◽  
Quantum Limit ◽  
Recording Density

Patterned Magnetic Recording Media – Issues and Challenges

2016 ◽  
Vol 1817 ◽  
Author(s):  
Horia Gavrila ◽  
Doina Elena Gavrila
Keyword(s):  
Thermal Stability ◽  
New Media ◽  
Magnetic Recording ◽  
Large Fraction ◽  
Hard Disk Drives ◽  
Anisotropy Field ◽  
Anisotropy Constant ◽  
Nano Particles ◽  
Recording Density ◽  
Geometry Parameter

ABSTRACTThe conventional magnetic recording approached the physical frontiers of the recording density. The magnetic recording must face the famous trilemma: In order to increase the recording density, smaller grain volumes are needed, but in order to ensure the thermal stability of recorded information, the anisotropy constant should be increased accordingly; what results is an increased anisotropy field, which requires higher writing fields. Such fields are unavailable with the maximum saturation magnetization obtainable with the magnetic materials of the current heads. In order to overcome these problems, new media structures have been proposed. The most promising is the bit-patterned magnetic media (BPM), intensively studied over the last years with the aim of obtaining obtain an ultra-high recording density of hard-disk drives. A BPM comprises monodisperse high-anisotropy nano-particles in a self-organized patterning. They have a higher thermal stability, a lower noise and a higher signal resolution, which leads to a higher recording density and a better SNR. They eliminate the transition noise and, due to the large fraction of the bit volume occupied by the magnetic dots, improve thermal stability. Nevertheless, some important issues such as long-range patterning, control of the surface roughness, signal readout, etc., remain critical problems to solve. Another challenge is the fact that recording on BPM is sensitive to the material and geometry parameter fluctuations that may lead to additional constraints and require tight synchronization of the write-field misregistration time and bit positions. A possible route to higher recording densities is to use a multilevel recording, where more than two states are stored per dot.

Thermally assisted magnetic recording with bit-patterned media to achieve areal recording density beyond 5Tb/in2

2012 ◽  
Vol 324 (3) ◽  
pp. 309-313 ◽  
Author(s):  
Fumiko Akagi ◽  
Masaki Mukoh ◽  
Masafumi Mochizuki ◽  
Junko Ushiyama ◽  
Takuya Matsumoto ◽  
...  
Keyword(s):  
Magnetic Recording ◽  
Bit Patterned Media ◽  
Patterned Media ◽  
Recording Density ◽  
Thermally Assisted Magnetic Recording

Recent advances and opportunities in magnetic recording materials

1993 ◽  
Vol 51 ◽  
pp. 1010-1011
Author(s):  
Mark H. Kryder
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Grain Boundaries ◽  
Magnetic Materials ◽  
Magnetic Recording ◽  
Magnetocrystalline Anisotropy ◽  
High Coercivity ◽  
Recording Density ◽  
The Future ◽  
Materials Used

Recording densities in magnetic recording products manufactured today are of the order of 200 Mbit/in. However, it is projected that densities as high as 10 Gbit/in will be achieved in the future. To achieve this, substantial improvements in the thin film magnetic materials used for magnetic heads and media are required.To support higher recording density in thin film media, it is necessary to increase the coercivity, while simultaneously achieving small grain size and small intergranular coupling. To achieve high coercivity, materials with large magnetocrystalline anisotropy are used, while to achieve small, well-isolated grains, special materials are used and deposited under conditions which promote either heavily voided grain boundaries or the segregation of non-magnetic species to the grain boundaries. It is also thought to be important to control the orientation of the crystallites so that a preferred axis of magnetization lies parallel to the direction of recording.

Improvement of Recording Density of Amorphous TbFeCo Magnetic Recording Layer on FeC Soft Magnetic Back Layer

2002 ◽  
Vol 41 (Part 2, No. 6B) ◽  
pp. L691-L693 ◽  
Author(s):  
Koji Matsumoto ◽  
Hiroyasu Kawano ◽  
Takeshi Morikawa ◽  
Keiji Shono
Keyword(s):  
Magnetic Recording ◽  
Soft Magnetic ◽  
Recording Layer ◽  
Recording Density

Materials for Magnetic-Tape Media

MRS Bulletin ◽  
1996 ◽  
Vol 21 (9) ◽  
pp. 35-41 ◽  
Author(s):  
Seiichi Onodera ◽  
Hirofumi Kondo ◽  
Takahiro Kawana
Keyword(s):  
Thin Film ◽  
Magnetic Recording ◽  
Magnetic Tape ◽  
Magnetic Particles ◽  
Low Cost ◽  
Video Recording ◽  
Magnetic Thin Films ◽  
Optical Recording ◽  
Digital Data ◽  
Recording Density

Magnetic recording has been responsible for the widespread and inexpensive recording of sound and video. Despite the availability of other means of storing data, such as optical recording and semiconductor devices, flexible magnetic-recording media have advantages such as (1) low cost, (2) stable storage, (3) a relatively high data rate, (4) a relatively short seek time, and (5) high-volumetric information density.The first commercially available magnetic-recording tapes were produced in 1947 by the 3M Company. Since that time, magnetic tapes have developed rapidly for use in audio, video, and digital-data recording systems.The linear-analogue technique is commonly used for most audio recorders. The magnetic tape is transported at a speed of several cm/s over a stationary head. On the other hand, helical-scanning rotary heads were developed for video recording, which afforded a high head-to-tape speed of more than several m/s and high recording-density capabilities. However high relative speed causes wear of the tape. The success of a tape in actual use depends critically on its tribological properties.Magnetic media are divided into two groups: (1) particulate media where magnetic particles are dispersed in a polymer binder with some additives and coated onto the substrate and (2) thin-film media in which monolithic, magnetic thin films are deposited onto the substrate in vacuum. The overwhelming preponderance of media fabricated to date have been coated media. However continuous demand for increasingly higher recording density has led to thin-film media.

Sign in / Sign up

Export Citation Format

Share Document