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.)

9:00 AM - 9:15 AM

[25a-E201-1] New physical origin of the temperature dependence of tunnel magnetoresistance: Crucial importance of interfacial s-d exchange interaction

〇Keisuke Masuda1, Terumasa Tadano1, Yoshio Miura1 (1.NIMS)

Keywords:tunnel magnetoresistance, s-d exchange interaction

Achieving high tunnel magnetoresistance (TMR) ratios at room temperature is essential for magnetic tunnel junctions (MTJs). However, previous experiments on various MTJs have reported a significant decrease in the TMR ratio with increasing temperature. Here, we theoretically study the origin of this phenomenon in a typical Fe/MgO/Fe(001) MTJ. Our idea for explaining the sharp reduction of the TMR ratio is to consider the s-d exchange interaction in ferromagnetic Fe layers. We calculated the temperature dependence of the TMR ratio by applying the Kubo-Greenwood formula to the tight-binding model with the s-d exchange interaction. We found that the calculated TMR ratio significantly decreases with increasing temperature, consistent with experimental results.