Navigation and service

Origin of the “Planar Hall Effect” Explained

September 11, 2011

Sometimes a seemingly minor cause can have a major effect; it is exactly this principle which governs the workings of so-called magnetoresistive sensors.  These register weak changes in a magnetic field through a significant change in the electrical resistance.  A well-known example of this is the giant magnetoresistance effect, the discovery of which earned the Jülich research scientist, Peter Grünberg, the Nobel Prize in Physics in 2007 and already soon led to the development of gigabyte hard disc drives. 

20110911mFigure1_jpgJülich physicists have determined the electrical resistance of a nanocrystalline cobalt-iron-boron alloy as a function of the magnetic field strength and the alignment of the magnetic field. (a) and (c) show the anisotropic magnetoresistance effect, (b) and (d) the planar Hall effect. The measurement results on the left and the theoretical calculations on the right show good agreement. For further information: Seemann et al., PRL 107, 086603 (2011).

The results of new research from physicists at the Peter Grünberg Institute in Jülich now show a magnetoresistive effect – previously considered only marginally application-relevant – in a new light.  Researchers are able to demonstrate that the so-called planar Hall effect can be classified as part of the group of anisotropic magnetoresistance effects, already used in many different applications in industry.  Furthermore, they are investigating, both experimentally and theoretically, the effects of temperature and the spatial orientation of the magnetization on the electrical resistance of a nanocrystalline cobalt-iron-boron alloy.  Their results will help in the development of sensors of the highest sensitivity which could be of use in the field of magnetic biosensorics.


The paper entitled “Origin of the Planar Hall Effect in Nanocrystalline Co60Fe20B20“ was published online in the August  edition of the journal “Physical Review Letters“ at DOI:10.1103/PhysRevLett.107.086603

Peter Grünberg Institut: