30 years ago: The GMR effect
A patent application that changed the way the world communicates
Prof. Dr. Peter Grünberg (2006)
30 years ago, on 16 June 1988, an invention was applied for a patent at the DPMA whose influence on our daily lives can hardly be overestimated. The application filed by the Jülich Nuclear Research Centre under the number DE3820475C1 was patented under the title "Magnetfeldsensor mit ferromagnetischer, dünner Schicht" (Magnetic field sensor with ferromagnetic, thin film).
Its inventor was the solid state physicist Dr. Peter Grünberg. He had observed that the electrical resistance between two ferromagnetic layers reacts sensitively to an external magnetic field when these are separated by a layer only a few atomic layers thick. As early as in the patent specification, the inventor emphasized that this was used for "reading magnetically stored data".
"Magnetfeldsensor mit ferromagnetischer, dünner Schicht" (DE3820475C1)
The effect recognized by Grünberg is now known as Giant Magnetoresistance (GMR). It led to a breakthrough in modern information technology by enabling the miniaturization of hard disks in computers, smartphones and MP3 players.
The importance of this invention quickly became apparent: Grünberg was awarded the Zukunftspreis des Bundespräsidenten (German President's Future Award) in 1989 and the European Commission's Inventors' Prize in 2006. In 2007 he received the Nobel Prize in Physics, together with the Frenchman Albert Fert, who had also observed the GMR effect independently of him.
In just a few years, Grünberg's discovery paved the way from patenting to industrial mass production and is thus a prime example of the rapid implementation of basic research into practical application and market readiness. That is why the DPMA dedicates its own poster to her in its gallery with inventions that have had a decisive influence on our everyday lives.
Grünberg, who had worked in Jülich since 1972 and always remained loyal to the Forschungszentrum, received numerous further awards and honorary doctorates. He died only a few weeks ago, in April 2018. Jülich praised him as "an outstanding scientist who has set standards worldwide in the field of solid state research. Without exaggeration one can say: Peter Grünberg and his discovery of giant magnetoresistance have decisively changed all our lives".
Picture: Forschungszentrum Jülich
Last updated: 25/03/19