1202.4218 (Hao Yu)

Stress in Spin-Valve Nanopillars due to Spin Transfer    [PDF]

Hao Yu

We report a mechanical effect in spin-valve nanopillars due to spin transfer.
A polarized current carrying electron spins transfers torque to local
magnetization and leads to a magnetic switching of free layer. Like classical
Einstein-de Haas effect, the conservation of angular momentum needs the free
layer to offset the change of angular momentum and then a mechanical rotation
occurs. The free layer is not free standing, so the mechanical angular momentum
will be revealed as stress and strain. We study the effect of a spin induced
stress in a nanopillar device with in-plane magnetization. Our calculations
show that the tress in as device is dependent on frequency and the ratio of
length/thickness and about 1 MPa at GHz. It is concluded that the stress owing
to spin transfer is much less than the internal stress of film and does not
introduce damage to the device.

View original: http://arxiv.org/abs/1202.4218