Title :
Enhanced Thermal Stability in Perpendicular Top-Pinned Magnetic Tunnel Junction With Synthetic Antiferromagnetic Free Layers
Author :
Yoshida, Chikako ; Takenaga, Takashi ; Iba, Yoshihisa ; Yamazaki, Yasuyuki ; Noshiro, Hideyuki ; Tsunoda, Koji ; Hatada, Akiyoshi ; Nakabayashi, Masaaki ; Takahashi, Asami ; Aoki, Masaki ; Sugii, Toshihiro
Author_Institution :
Low-power Electron. Assoc. & Project (LEAP), Tsukuba, Japan
Abstract :
Synthetic antiferromagnetic (SAF) free layers consisting of [Co (0.3 nm)/Pd (0.7 nm)]n/Ru/Ta/CoFeB were investigated for use in the free layers of top-pinned magnetic tunnel junctions (MTJs). We found that interlayer exchange coupling properly provides thermal stability when the saturation magnetization of the CoPd layer is less than that of the CoFeB layer. Furthermore, we demonstrated that the thermal stability factor of the top-pinned MTJ with [Co (0.3 nm)/Pd (0.7 nm)]n=1/ Co (0.3 nm)/Ru/Ta/CoFeB- SAF free layers was improved without increasing the intrinsic switching current.
Keywords :
antiferromagnetic materials; boron alloys; cobalt; cobalt alloys; exchange interactions (electron); ferromagnetic materials; interface magnetism; iron alloys; magnetic tunnelling; magnetisation; palladium; ruthenium; tantalum; thermal stability; Co-Pd-Ru-Ta-CoFeB; enhanced thermal stability; interlayer exchange coupling; perpendicular top-pinned magnetic tunnel junction; saturation magnetization; switching current; synthetic antiferromagnetic free layers; Junctions; Magnetic hysteresis; Magnetic resonance imaging; Magnetic tunneling; Saturation magnetization; Switches; Thermal stability; Perpendicular magnetic anisotropy; synthetic antiferromagnetic free layer; thermal fluctuation; top-pinned magnetic tunnel junction;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2013.2248350
