The authors have fabricated epitaxially grown spin-valve-type magnetic tunnel junctions with L 21 - Co2 Fe Al0.5 Si0.5 full-Heusler alloys for top and bottom electrodes and a MgO barrier. For MgO thickness tMgO =1.5 nm, tunnel magnetoresistance (TMR) ratio and resistance and area product (RA) initially increase up to around 350 °C and then decrease by annealing, while for tMgO =2.0 and 2.5 nm, the TMR ratio increases with annealing temperature and peaks around 500 °C. The TMR ratio up to 175% at RT and thermal stability up to 500 °C have been achieved for tMgO =2.0 nm, suggesting the large tunneling spin polarization and high thermal stability for Co2 Fe Al0.5 Si0.5 with L 21 structure.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)