Nanoscale Magnetic Tunnel Junctions

Description
At the UofU we developed magnetic films based our semiconducting, room temperature magnet V[TCNE]x (TCNE = tetracyanoethylene, x~2), which potentially can be used as an alternative spin injector. We are exploiting classical experimental approaches to construct magnetic tunnel junction, which provides insight into spin transport and spin injection in the V[TCNE]x film. The device consisting of FM layers separated by nonmagnetic tunnel layer in which the tunneling probability of spin-polarized electrons depends upon the relative magnetizations of the two FM electrodes. Thus the tunnel conductance can be changed by the external magnetic field. We use ~50 nm of Fe50Co50 alloy or MnAs (Tc = 320 K) as the FM layer, and MgO, SiO2 or GaAs as a thin (~1 nm) tunnel barrier with V[TCNE]x as a spin-injector (~100 nm).

Implications
Realization of semiconductor spintronics devices requires efficient electrical injection of spin-polarized carriers as well as their efficient transport and manipulation within a host medium. Spin lifetimes in n-GaAs can exceed hundreds of nanoseconds, enabling the transport of coherent spin packets over hundreds of micrometers and their manipulation with optical pulses or local electric fields.

Research Group Contacts
J. S. Miller, Department of Chemistry, 585-5455, jsmiller@chem.utah.edu

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