Local Magneto-Transport in [Co/Pd]IrMn Thin Films

We have been studying the effects that X-Ray illumination may have on the magnetic domain memory exhibited by [Co/Pd]IrMn multilayered thin-films. Our samples consist of a multilayer made of 4 Å thick layers of Co alterning with 7 Å thick layers of Pd, repeated 12 times, combined with a 24 Å thick antiferromagnetic layer of an Ir-Mn alloy. Through experiments done previously at a synchrotron facility, we have seen an unexplained loss in magnetic domain memory of the sample. Our current goal is to probe this unexplained loss in magnetic domain memory though the use of magneto-transport measurements in order to determine if the loss of magnetic domain memory is caused by of a loss of exchange bias between the ferromagnetic and antiferromagnetic layers. We take these measurements by applying a current across the sample, while applying a magnetic field perpendicular to the sample, and measuring the voltage across the sample in order to measure both the Hall Effect and the magnetoresistance of the sample. I will show measurements taken at temperatures ranging from high (300 K) down to low temperature (10 K), that allow tracking the amount of exchange bias in the material throughout the blocking transition.