Magnetic anisotropy and domain duplication in transport properties of tunnel junctions

A tunnel magnetoresistance signal is used for probing the relative orientat ions of the local magnetization in the two magnetic electrodes of a tunnel junction. Minor magnetoresistance loops are studied as a function of the re turn field in order to change the domain configuration of the hard layer. D omain structure duplication of the hard layer template into the soft layer is observed. This effect is shown to be driven by the magnetic anisotropy o f the hard layer. Reducing this anisotropy leads to domain duplication but with effects nondiscernible in the tunnel magnetoresistance (TMR) signal. H owever, a signature of the 360 degrees domain walls is then observed on the TMR signal.