Magnetic Tape: The Challenge of Reaching Hard-Disk-Drive Data Densities on Flexible Media

Abstract

By the end of 2006, the areal density of magnetic recording on tape will approach that seen in hard disk drives of the early to mid-1990s.These operating conditions are reviewed in relation to the operating conditions deemed necessary for the future of magnetic data storage on tape.What results is a clear set of tasks, encompassing both materials and systems architecture issues, to achieve very high-density data storage on magnetic tape, leading to 10 Tbyte tape cartridge capacities and higher.The key to achieving on tape the areal densities of tens to hundreds of Gbit in.2, common in hard disk drives (HDDs), lies primarily in the properties of the medium itself.As for volumetric density of the storage entity, HDDs and tape cartridges are roughly equivalent.The mechanical dimensional uncertainties that accompany the use of flexible, as opposed to rigid, media means that both the mechanical and magnetic properties of materials play a key role in the future of tape.The need for new architectures to overcome the track placement problem that results from increasing track density on flexible media are reviewed, as well as the “particles in a binder” concept that has served so well as the physical basis of tape media over the past 50 years.

Polymer‐Based Magnetoelectric Materials

“…As the current electronic market demands are intimately related to the use of flexible materials,143 not only the magnetic/dielectric properties of materials will play a key role in the future but also their mechanical properties 144. In this way, the substitution of PZT by a polymer in bilayer four‐state ME memories will meet these new challenges.…”

Control Methods in Data-Storage Systems

“…In the past, the linear density increased much more strongly than the track density for tape systems [23], [24]. An increase in linear density translates into a smaller distance between adjacent bit cells, leading to an increase in inter-symbol interference.…”

Current-induced domain wall motion in nanoscale ferromagnetic elements

“…at (2) This torque is perpendicular to the adiabatic torque and although its amplitude is expected to be small in 3d metal with f3sr ;::::: 0.01, it significantly alters the dynamics of the DW and in particular can determine the critical current density and the terminal velocity of the DW. Two different contributions have been identified for this torque.…”

“…One of the key problems is the mechanical motion ofthe media, which poses reliability questions and can lead to catastrophic failure in the case of mechanical shock. Another successful magnetic memory is magnetic tape, which has a huge capacity but obvious limitations when it comes to random access times [2]. Again tape drive~ physically move the media (tape), which leads to wear.…”

“…Cross-section of a wire with the calculated distribution of the Oersted fi eld. The current (10 12 A m-2 flow s homogeneously in the wire in the -z direction. The wire dimensions are 5.6 nm x 2 /-Lm (x and yare plotted at different scales).…”