Giant-Magnetoresistance (GMR) describes the effect that the electrical resistivity of a structure consisting on thin magnetic and non-magnetic films ("magnetic multilayer") depends on the relative orientation of the magnetization vectors of adjacent magnetic layers. This effect was discovered only in 1988 by P. Grünberg (Research Center Jülich) and A. Fert (University Paris).

This effect can be used to detect magnetic fields by a change of resistivity, if the external field changes the relative orientation of the magnetic layers, e.g. from antiparallel to parallel.
Since 1998 the GMR-effect is applied in high-density readheads of computer harddisks and allowed for an increase of the storage density by about one order of magnitude.
The animation first explains the setup of a computer harddisk and how data is stored and retrieved. The main part presents a detailed but comprehensible picture of the GMR-effect.


Technical information:
There are two versions of the animation available, a PC-version and a MacIntosh version. At the moment we cannot yet provide a UNIX version, sorry. The download consists of a packed file (.zip or .sit) of about 4.7 Mbytes. After unpacking on your computer (using e.g. WinZip or Stuffit Expander) you will get an executable flash application with sound. Have fun!