The GMR (giant magnetoresistance) effect propelled modern information technology a huge step forward: thanks to this, it was possible to develop read heads for computer hard drives in the 1990s and increase the drives’ storage capacity to gigabytes. The innovation arose from the following finding: the electrical resistance of a structure consisting of thin magnetic and non-magnetic layers depends on the orientation of the magnetic layers’ magnetization in relation to each other. When magnetized in opposite directions, the electrical resistance is much higher than when magnetized in the same direction. The GMR effect was discovered by two physicists independently in 1988: Peter Grünberg from the Jülich Research Center and Frenchman Albert Fert from Paris-Sud University. A few years later, industry also recognized the advantages. In 1997, for example, IBM produced the first commercial hard drive using the GMR effect. The principle has also been applied to magnetic field sensors in cars.
More capacity, better performance
Peter Grünberg and Albert Fert won the 2007 Nobel Prize in Physics. or their discovery. Peter Grünberg died on April 9, 2018, at the age of 78. The Jülich Research Center, where the physicist worked for more than 45 years, paid tribute to him as an “outstanding scientist who raised the bar worldwide in the field of solid-state research.” Back in 1989 he was awarded the German Federal President’s Future Prize and in 2006 the European Inventor Award. In 2008, the town of Jülich made him an honorary citizen.
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