Researched
Giant Magnetoresistance & Spintronics
In 1988 Albert Fert and Peter Grünberg found that the resistance of thin magnetic layers depends on electron spin; GMR read heads put it into hard disks from 1997.
Open in the interactive tree →Fert in Paris saw the resistance of iron-chromium multilayers fall by up to 50% at 4.2 K; Grünberg in Jülich saw about 3% at room temperature. IBM's Stuart Parkin and colleagues turned the effect into the spin valve, a sensitive magnetic-field sensor, and IBM's Deskstar 16GP, announced in November 1997, is credited as the first product with GMR heads. Tunnel magnetoresistance, with about ten times the effect, has since replaced GMR in drive heads and in magnetic memory (MRAM). Fert and Grünberg shared the 2007 Nobel Prize in Physics.
Prerequisites
- Solid-State Physics & Bands1931The effect comes from spin-dependent electron scattering in thin magnetic layers.
- Hard Disk Drive1956Its first large use was the read head of hard disk drives.