Spin-torque switching window, thermal stability, and material parameters of MgO tunnel junctions

We study the use of in-plane magnetized free layers with artificially lowered effective magnetization, in the context of spin-torque random access memories with magnetic tunnel junctions. We determine the field-voltage window for direct overwrite switching and thermal stability. We relate them to the magnetic constants extracted from the telegraph noise and high frequency noise exhibited by the junctions under specific conditions.

[1]  M. Julliere Tunneling between ferromagnetic films , 1975 .

[2]  Berger Emission of spin waves by a magnetic multilayer traversed by a current. , 1996, Physical review. B, Condensed matter.

[3]  J. Slonczewski Current-driven excitation of magnetic multilayers , 1996 .

[4]  Jonathan Z. Sun Spin-current interaction with a monodomain magnetic body: A model study , 2000 .

[5]  Ralph,et al.  Current-driven magnetization reversal and spin-wave excitations in Co /Cu /Co pillars , 1999, Physical review letters.

[6]  M. Kostylev,et al.  Spin-wave excitations in finite rectangular elements of Ni 80 Fe 20 , 2005 .

[7]  Akio Fukushima,et al.  Estimation of thermal durability and intrinsic critical currents of magnetization switching for spin-transfer based magnetic random access memory , 2005 .

[8]  Koji Ando,et al.  Ultralow resistance-area product of 0.4Ω(μm)2 and high magnetoresistance above 50% in CoFeB∕MgO∕CoFeB magnetic tunnel junctions , 2006 .

[9]  H. Ohno,et al.  Single-shot time-resolved measurements of nanosecond-scale spin-transfer induced switching: stochastic versus deterministic aspects. , 2008, Physical review letters.

[10]  J. Katine,et al.  Device implications of spin-transfer torques , 2008 .

[11]  H. Ohno,et al.  Current-Induced Magnetization Switching in MgO Barrier Magnetic Tunnel Junctions With CoFeB-Based Synthetic Ferrimagnetic Free Layers , 2008, IEEE Transactions on Magnetics.

[12]  J. Katine,et al.  Distortion of the Stoner-Wohlfarth astroid by a spin-polarized current , 2009, 0902.2337.

[13]  T. Devolder,et al.  Effect of patterning on the saturation magnetization in MgO based nanopillars , 2009 .

[14]  H. Ohno,et al.  A perpendicular-anisotropy CoFeB-MgO magnetic tunnel junction. , 2010, Nature materials.

[15]  T. Devolder,et al.  Quantized spin-wave modes in magnetic tunnel junction nanopillars , 2009, 0907.3792.