Absence of induced moment in magnetic tunnel junction barriers

To confirm the theoretical underpinnings of spin-polarized transport, we have performed x-ray magnetic circular dichroism experiments on samples exhibiting a ferromagnet-insulator interface grown using processes which have yielded junctions with appreciable tunneling magnetoresistance. Within experimental sensitivity, no magnetic moment induced due to the proximity of the ferromagnet was detected on any atomic barrier site using this element-specific technique.