tunnel magnetoresistance abbr., TMR (rus. магнетосопротивление, туннельное otherwise туннельное магнитосопротивление) — effect of changes in electrical resistance between two ferromagnetic regions, separated by a thin dielectric layer due to tunnelling of a spin-polarised carriers induced by the magnetic field.

Description

The effect of tunnelling magnetoresistance is similar to that of giant magnetoresistance, but the ferromagnetic regions are separated by non-conductive insulating layers. In this case, the transport of charge carriers through the insulating layer is provided solely by quantum-mechanical effects. Examples of systems using tunnel magnetoresistance include composites, in which ferromagnetic grains are arranged in an insulating matrix, and layered structures, in which magnetic layers are separated by thin dielectric layers. Recently, magnetoresistive random access memory (MRAM) has been created on the basis of tunnelling magnetic resistance. The effect is also used in the reading heads of hard drives. This effect is one of the main effects that can be practically implemented in spintronics devices.

Illustrations

Example of a structure characterized by the occurrence of tunnel magnetoresistance effect [2].
Example of a structure characterized by the occurrence of tunnel magnetoresistance effect [2].

Author

  • Zaitsev Dmitry D.

Sources

  1. Gorbenko O.Ju., Bosak A. A. Magnetoresistance manganites at low magnetic fields and its application (in Russian)// Sensor. №2. 2002. 28–44pp.
  2. Baklickaja O. Nobel Prizes in 2007 Giant magnetoresistance — a triumph of basic science (in Russian) // Nauka i zhizn'. 2007. №11. —www.nkj.ru/archive/articles/12042/ (reference date: 12.12.2011).

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