[17p-P10-1~93] 10 Spintronics and Magnetics（Poster）

▲ [17p-P10-86] Free-layer size dependence of magnetic anisotropy in nanoscale CoFeB/MgO magnetic tunnel junctions

〇(M2)Motoya Shinozaki¹, Igarashi Junta¹, Sato Hideo^2,3,4, Ohno Hideo^1,2,3,4,5 (1.Tohoku Univ. RIEC, 2.Tohoku Univ. CSIS, 3.Tohoku Univ. CSRN, 4.Tohoku Univ. CIES, 5.Tohoku Univ.WPI-AIMR)

Keywords:Magnetic tunnel junction, process, ferromagnetic resonance

We investigate free-layer size D dependence of effective anisotropy field in nanoscale CoFeB/MgO magnetic tunnel junctions by homodyne-detected ferromagnetic resonance. The effective anisotropy field H_K^eff monotonically increases with decreasing D for a device with the reference-layer size much larger than the free-layer size. In contrast, H_K^eff does not increase in a monotonic manner for a device with the reference-layer size comparable to the free-layer size. We reveal that the difference can be explained by the variation of anisotropy field in the vicinity of the device edge.