Leighton Group research uncovers new spintronic effect in aluminum

A recent publication from the Leighton Group in CEMS, appearing this week in Physical Review Letters, reports an unanticipated spintronic effect in the “simple” metal aluminum. In metals, it is well known that the spin lifetime and electron scattering time are related by a constant, known as the Elliott-Yafet constant. In this work, aluminum thin films were studied in nanoscale spin transport devices (see figure) over a wide thickness range (8-300 nm), revealing for the first time that this “constant” is in fact strongly thickness-dependent, i.e., it exhibits a finite-size effect. A model was developed to show that this arises due to strong spin relaxation at surfaces/interfaces, with direct implications for next generation read heads in hard disk drives.

The work was performed by graduate student Justin Watts, post-doc Joe Batley, and undergraduates Nate Rabideau and Jared Hoch, working with collaborators in U of M Physics and the University of Liverpool (UK). Critical parts of the work were performed in the U of M Char Fac and the MN Nano Center, and the work was supported by NSF, ASRC, and Seagate Technology.