A giant magnetoresistance ratio of 30% at 4.2 K and 18% at 300 K was observed for the first time in an Fe/Al2O3/Fe junction. The conductance at room temperature was expressed well by G=96.2 (1 + 0.09 cos θ)(Ω-1), where θ is the angle between the magnetizations of two iron electrodes. The dependence of the magnetoresistance ratio, saturated resistance and also the tunneling current on temperature were measured in the range 4.2-300 K. The results support the claim that the giant magnetoresistance is due to the magnetic tunneling of electrons between the electrodes through the thin Al2O3 insulator.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics