Daniel J. Coady, Amanda C. Engler, et al.
ACS Macro Letters
Magnetically engineered magnetic tunnel junctions (MTJs) show promise as non-volatile storage cells in high-performance solid-state magnetic random access memories (MRAM)1. The performance of these devices is currently limited by the modest (<∼70%) room-temperature tunnelling magnetoresistance (TMR) of technologically relevant MTJs. Much higher TMR values have been theoretically predicted for perfectly ordered (100) oriented single-crystalline Fe/MgO/Fe MTJs. Here we show that sputter-deposited polycrystalline MTJs grown on an amorphous underlayer, but with highly oriented (100) MgO tunnel barriers and CoFe electrodes, exhibit TMR values of up to ∼220% at room temperature and ∼300% at low temperatures. Consistent with these high TMR values, superconducting tunnelling spectroscopy experiments indicate that the tunnelling current has a very high spin polarization of ∼85%, which rivals that previously observed only using half-metallic ferromagnets2. Such high values of spin polarization and TMR in readily manufactureable and highly thermally stable devices (up to 400°C) will accelerate the development of new families of spintronic devices.
Daniel J. Coady, Amanda C. Engler, et al.
ACS Macro Letters
J.H. Stathis, R. Bolam, et al.
INFOS 2005
Elizabeth A. Sholler, Frederick M. Meyer, et al.
SPIE AeroSense 1997
A. Krol, C.J. Sher, et al.
Surface Science