In spintronics, the spin dependent transport properties of ferromagnets (Fs) lie at the heart of devices working principles. Conversely, antiferromagnets (AFs) are so far used for their magnetic properties only. However, spin dependent transport with AFs is of high interest: spin absorption lengths are expected to be longer in AFs than in Fs. This, together with the fact that AFs show no stray fields, would permit lower power consumption and ultimate downsize scalability.
The aim of this study was to measure spin penetration depth and spin absorption mechanisms in AFs. These are key data for anyone willing to use AFs in spintronics. Given that AFs possess no net magnetization, the traditional experimental methods for Fs do not apply. We achieved our goals by use of a specific and complex method involving a resonant F and ‘spin pumping’ phenomenon by a neighbouring AF. In particular, we unravelled traditional metallic AFs: IrMn and FeMn. Among the numerous perspectives one can think of the effects of the interfaces and AF core crystallinity on the spin penetration depth.
This work results from a collaboration between the SPINTEC laboratory and Dr W. E. Bailey from the Columbia University at New York.
P. Merodio et al, ‘Penetration depth and absorption mechanisms of spin currents in Ir20Mn80 and Fe50Mn50 polycrystalline films by ferromagnetic resonance and spin pumping’, Appl. Phys. Lett. 104, 032406 (2014).
Last update : 11/05 2014 (1077)