The 69th JSAP Spring Meeting 2022

Presentation information

Oral presentation

10 Spintronics and Magnetics » 10.3 Spin devices, magnetic memories and storages

[25a-E201-1~11] 10.3 Spin devices, magnetic memories and storages

Fri. Mar 25, 2022 9:00 AM - 12:00 PM E201 (E201)

Masuda Keisuke(物材機構), Shoya Sakamoto(Tokyo Univ.)

9:15 AM - 9:30 AM

[25a-E201-2] Giant tunnel magnetoresistance in Fe/Mg4Al-Ox/Fe(001) magnetic tunnel junctions

Thomas Scheike1, Zhenchao Wen1, 〇Hiroaki Sukegawa1, Seiji Mitani1 (1.NIMS)

Keywords:tunnel magnetoresistance, magnetic tunnel junction

Recently, we demonstrated significantly large TMR ratios using a conventional Fe/MgO/Fe(001) MTJ structure; 417% at room temperature (RT) (914% at 5 K) is almost twice (three times) as large as the typical ratios in Fe/MgO/Fe reports. However, due to the large lattice mismatch between Fe and MgO, many misfit dislocations are introduced at their interfaces, which limits further improvement of the TMR ratio. In this study, we report enhanced TMR ratios using a Mg-rich spinel barrier, Mg4Al-Ox. We observed the maximum TMR ratio is 429% at RT. At 10 K, the TMR ratio exceeds thousand percent (up to 1,034%), reaching typical theoretical values of Fe/MgO/Fe(001). The TMR ratio shows significant oscillatory behavior with a ~0.31 nm period and a large peak-to-valley difference of 125% at RT. These features may be attributed to improved barrier interfaces by lattice-tuning effect of a spinel MgAl2O4-based barrier.