Magnetic Tunnel Junction
A magnetic tunnel junction (MTJ) consists of two layers of magnetic metal, such as cobalt-iron,
separated by an ultrathin layer of insulator, typically aluminum oxide with a thickness of about 1 nm. The
insulating layer is so thin that electrons can tunnel through the barrier if a bias voltage is applied
between the two metal electrodes. In MTJs the tunneling current depends on the relative orientation of
magnetizations of the two ferromagnetic layers, which can be changed by an applied magnetic field. This
phenomenon is called tunneling magnetoresistance (TMR).
Nowadays MTJs that are based on transition-metal ferromagnets and Al2O3 barriers can be fabricated
with reproducible characteristics and with TMR values up to 50% at room temperature. Recently large
values of TMR observed in crystalline MTJs with MgO barriers further boosted interest in spin
dependent tunneling. MTJs are promising for applications in magnetic storage and sensor industry.
http://physics.unl.edu/~tsymbal/tsymbal_files/TMR/sdt_files/page0001.html
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A magnetic tunnel junction (MTJ) consists of two layers of magnetic metal, such as cobalt-iron,
separated by an ultrathin layer of insulator, typically aluminum oxide with a thickness of about 1 nm. The
insulating layer is so thin that electrons can tunnel through the barrier if a bias voltage is applied
between the two metal electrodes. In MTJs the tunneling current depends on the relative orientation of
magnetizations of the two ferromagnetic layers, which can be changed by an applied magnetic field. This
phenomenon is called tunneling magnetoresistance (TMR).
Nowadays MTJs that are based on transition-metal ferromagnets and Al2O3 barriers can be fabricated
with reproducible characteristics and with TMR values up to 50% at room temperature. Recently large
values of TMR observed in crystalline MTJs with MgO barriers further boosted interest in spin
dependent tunneling. MTJs are promising for applications in magnetic storage and sensor industry.
http://physics.unl.edu/~tsymbal/tsymbal_files/TMR/sdt_files/page0001.html
Next
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