Abstract
-Fe(001)/Mg/MgO/Fe- and -Fe(001)/Mg/MgO/Mg/Fe- magnetic tunnel junctions (MTJs) with Mg interlayers are studied by first-principles calculations. We find that the Mg interlayer is able to preserve the preferential transmission of the majority-spin states with Δ1 symmetry, which dominates the spin-dependent electron transport in MTJs with MgO barrier. A monoatomic layer of Mg at the electrode/barrier interface does not decrease the tunneling magnetoresistance (TMR) ratio nearly as much as a similar layer of iron oxide. We also find that at a certain Mg thickness the TMR is strongly influenced by resonant tunneling in the minority-spin channel. These resonances are due to the coupling between the quantum-well states within the Mg interlayer to the interfacial resonance states on the Fe/Mg interface. The calculated results are used to explain experimental measurements of MTJs with Mg interlayers.
Original language | English |
---|---|
Article number | 054405 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 82 |
Issue number | 5 |
DOIs | |
State | Published - Aug 4 2010 |
Externally published | Yes |