[14a-2J-1~12] 10.3 Giant magnetoresistance (GMR), tunnel magnetoresistance (TMR) and magnetic recording technologies

▼ [14a-2J-8] In-plane aspect ratio dependence of thermal stability and intrinsic critical current
in CoFeB/MgO magnetic tunnel junctions with perpendicular anisotropy

〇Eriko Hirayama¹, Shun Kanai^1,2, Hideo Sato^2,3, Fumihiro Matsukura^1,2,4, Hideo Ohno^1,2,3,4 (1.LNS-RIEC, Tohoku Univ., 2.CSIS, Tohoku Univ., 3.CIES, Tohoku Univ., 4.WPI-AIMR, Tohoku Univ.)

Keywords:magnetic tunnel junction

To investigate the influence of the anisotropy on the properties of magnetic tunnel junctions (MTJs), we fabricate elliptical MTJs with a perpendicular magnetic easy axis with various in-plane aspect ratios (ARs), and evaluate their thermal stability factor and intrinsic critical current for magnetization switching. The in-plane magnetic-field angle dependence of the junction resistance shows that the in-plane anisotropy field increases with increasing AR, and its value is consistent with that expected from the shape-dependent demagnetizing factors. Thermal stability factor and intrinsic critical current do not show clear dependence of AR in agreement with magnetization switching through the nucleation of domains.