Magnetic Domain Memory in Thin Films*

Exchange coupling between the ferromagnetic and anti-ferromagnetic layers in [Co/Pd]/IrMn film causes a phenomenon known as magnetic domain memory (MDM), where the material returns to the same magnetic domain configuration after a magnetic field has been applied, even all the way to saturation. Information about MDM is obtained through coherent x-ray resonance magnetic scattering (XRMS) images taken using synchrotron radiation. Previous results showed that the degree of MDM depends on the magnitude of the field being applied when cooling the material below a certain blocking temperature. More recent experiments appear to indicate a disappearance of the MDM and we are investigating the cause of this loss. My particular research has focused on varying certain parameters in the cross-correlation process we use to determine the MDM. I will also show new magneto-transport data collected at synchrotron facility at different temperatures and in different conditions to investigate a possible effect of x-ray illumination causing a loss of MDM.