Spin transfer torque devices utilizing the giant spin Hall effect of tungsten

@article{Pai2012SpinTT,
  title={Spin transfer torque devices utilizing the giant spin Hall effect of tungsten},
  author={Chi‐Feng Pai and Luqiao Liu and Y. Li and Hsin-wei Tseng and Daniel C. Ralph and Robert A. Buhrman},
  journal={Applied Physics Letters},
  year={2012},
  volume={101},
  pages={122404}
}
We report a giant spin Hall effect in β-W thin films. Using spin torque induced ferromagnetic resonance with a β-W/CoFeB bilayer microstrip, we determine the spin Hall angle to be |θSHβ-W|=0.30±0.02, large enough for an in-plane current to efficiently reverse the orientation of an in-plane magnetized CoFeB free layer of a nanoscale magnetic tunnel junction adjacent to a thin β-W layer. From switching data obtained with such 3-terminal devices, we independently determine |θSHβ-W|=0.33±0.06. We… 

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