[12p-A501-1~16] 10.4 Semiconductor spintronics, superconductor, multiferroics

▼ [12p-A501-6] Large tunnel magnetoresistance in a fully epitaxial Fe/ MgO/ Fe/ γ-Al₂O₃/ Nb:SrTiO₃ double-barrier magnetic tunnel junction

〇(D)Ryota Suzuki¹, Yuriko Tadano¹, Masaaki Tanaka¹, Shinobu Ohya¹ (1.The Univ. of Tokyo)

Keywords:spintronics, tunnel magnetoresistance, magnetic tunnel junction

Enhancing the tunnel magnetoresistance (TMR) is important for boosting the performance of spintronics devices. There has been an interesting proposal to enhance the TMR by injecting carriers only with a small in-plane wave vector k_|| from an electrode with a small electron density into magnetic tunnel junctions (MTJs) [1-3]. In this study, we have grown an MTJ structure composed of Co (15 nm)/ Fe (18 nm)/ MgO (3 nm)/ Fe (10.7 nm)/ γ-Al₂O₃ (1.6 nm) on a Nb-doped (0.5 wt%) SrTiO₃ (001) substrate by molecular beam epitaxy (MBE). We obtained large TMR ratios of 219 % at 300 K and 366 % at 3.7 K, which are larger than the typical TMR ratios reported for the Fe/ MgO / Fe structures (180% at 293 K, 247% at 20 K) [4].

[1] S. Ohya et al., Phys. Rev. Lett. 104, 167204 (2010).
[2] G. Autès et al., Phys. Rev. Lett. 104, 217202 (2010).
[3] R. Suzuki et al, Appl. Phys. Lett. 112, 152402 (2018).
[4] S. Yuasa et al., Nat. Mater. 3, 868 (2004).