Veranstaltungsdetails

22.6.2006, 15:00
Jungiusstr. 9, Hörsaal III

SFB 668 - Kolloquium

Dr. Andreas Berger (IBM / Hitachi, USA):

The Computer Hard Disk Drive - Nanotechnology on a 100 Dollar Budget

Nanotechnology is expected to change and shape our lives in the 21st century. It is, however, not just a far out vision, but actually part of our daily lives already. The computer Hard Disk Drive (HDD), which is found in all Personal Computers and increasingly in consumer electronics applications, is one of the technologies that requires and utilizes nm-scale precision already today.
In my talk, I will give an introduction into HDD technology and outline some of today´s challenges related to the nanometer scale of its components. In detail, I will present the magnetics and materials issues of modern disk media and focus on the highly successful Anti-Ferromagnetically Coupled (AFC)-media1 as well as the recently introduced technology of perpendicular recording. Using this recording technology, we succeeded last year[2] in demonstrating the industry´s highest data density at 230 gigabits per square inch (Gb/in²).
Besides their commercial applications, disk media-type magnetic nanostructures can also be utilized as nano-laboratory for the study of magnetic properties and effects on the nm-length scale like interlayer exchange coupling[3] or exchange bias[4,5], for instance.

[1] E. E. Fullerton, D. T. Margulies, N. Supper, H. Do, M. Schabes, A. Berger, and A. Moser, "Antiferromagnetically-coupled magnetic recording media", IEEE Trans. MAG 39, 639 (2003)
[2] John Markov, "Hitachi Achieves Storage Record for Disk Drives", NY Times, April, 4th 2005
[3] A. Moser, A. Berger, D. T. Margulies, and E. E. Fullerton, "Magnetic domain size tuning of biquadratic exchange coupling in magnetic thin films", Phys. Rev. Lett. 91, 097203 (2003)
[4] A. Berger, D. T. Margulies, and H. Do, "Magnetic Hysteresis Loop Tuning in Antiferromagnetically-Coupled Bilayer Structures", Appl. Phys. Lett. 85, 1571 (2004)
[5] Ch. Binek, S. Polisetty, Xi He, and A. Berger, "Exchange Bias training effect in coupled all ferromagnetic bilayer structures", Phys. Rev. Lett. 96, 067201 (2006)