Abstract
We have observed the transport properties in magnetic tunnel junction with the multilayered structure: La0.67Sr0.33MnO3 (50 nm)/Al-O (1 nm)/CoFeB (5 nm)/Ta (10 nm)/Ru (10 nm). The maximum normal tunneling magnetoresistance (TMR) ratio was found to be 12.4% at a temperature range around 100 K, and the maximum inverse TMR ratio was observed to be ∼3% at a temperature of 5 K. The inverse TMR decreases with increasing temperature until it reaches a temperature range of around 50 K, whereby it switches to the normal TMR behavior. The appearance of inverse TMR at low temperatures is attributed to the presence of minority-spin density of states (DOS) of half-metal La0.67Sr0.33MnO3 around the Fermi level present at the half-metal-insulator interface. The vanishing of inverse TMR and increase of normal TMR above certain temperature range is due to no contribution from the minority-spin DOS in the tunneling process. These results were found to be reproducible and the TMR ratio of more than 3% and 11% was obtained at room temperature before and after annealing at a temperature of 235 K for an annealing time of one hour, respectively.
Original language | English |
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Article number | 5467617 |
Pages (from-to) | 2383-2386 |
Number of pages | 4 |
Journal | IEEE Transactions on Magnetics |
Volume | 46 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2010 Jun |
Keywords
- Half-metal LSMO
- Inverse tunneling magnetoresistance (TMR)
- Magnetic tunnel junction (MTJ)
- Minority-spin density of states (DOS)
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering