Observation of spin-transfer switching in deep submicron-sized and low-resistance magnetic tunnel junctions

TL;DR

This paper reports the observation of spin-transfer induced magnetization switching in deep submicron magnetic tunnel junctions with low resistance, demonstrating current-induced switching at high current densities and its dependence on magnetic field.

Contribution

It presents the first observation of spin-transfer switching in small, low-resistance magnetic tunnel junctions, confirming the effect's applicability at reduced device sizes.

Findings

Switching observed at current densities around 8e6 A/cm2

Switching correlates with current-induced changes in resistance

Critical current density depends on applied magnetic field

Abstract

The spin-transfer effect has been studied in magnetic tunnel junctions (PtMn/CoFe/Ru/CoFe/Al2O3/CoFe/NiFe) with dimensions down to 0.1x0.2 um2 and resistance-area product RA in the range of 0.5-10 Ohm m2 (dR/R=1-20%). Current-induced magnetization switching is observed with a critical current density of about 8e6 A/cm2. The attribution of the switching to the spin-transfer effect is supported by a current-induced dR/R value identical to the one obtained from the R versus H measurements. Furthermore, the critical switching current density has clear dependence on the applied magnetic field, consistent with what has been observed previously in the case of spin-transfer induced switching in metallic multilayer systems.