Control of interlayer magnetostatic coupling in submicron-sized Fe/Au/Fe rings

摘要

We have investigated the inner diameter dependence of magnetostatic coupling in Fe/Au/Fe pseudospin valve (PSV) rings by the magneto-optical Kerr effect. Hysteresis loops of the soft layer with smaller inner diameter are considerably different from those found in single-layer rings maintaining the outer diameter. This is explained by the attenuation of circumferential shape anisotropy as the inner diameter decreases. The magnetostatic coupling is enhanced between the two Fe layers due to an increase of a stray field from ring edges. These results indicate that the magnetostatic coupling in the PSV rings is controlled by changing the inner diameter.