Magnetic Nano-Ring and Single Domain

We have patterned magnetic nano-ring and single domain structures of Ni on (011) PMN-PT substrate, and used MFM and X-PEEM technique to characterize the magnetic domain movement in patterned Ni nanostructures.

We have achieved a permanent 90° rotation in the magnetization direction of patterned rings using only electric field-induced magnetoelastic anisotropy. Using X-PEEM we have demonstrated the possibility of inducing a 90° uniform magnetization rotation due to an electric field in arrays of strain coupled artificial multiferroic nanostructures. Thanks to the hysteretic strain dynamics of the FE material, the effect can be nonvolatile and reversible constituting an important step towards the realization of a magnetoelectric MRAM cell. We have found that the multidomain structure of the FE single crystal leads to a complex strain-mediated magnetoelectric coupling. This suggests that realizing the full magnetoelectric stack at the nanoscale in order to achieve a single domain configuration in the FE as well as the FM is of primary importance not only for fulfilling large scale integration requirements but also for the achievement of reliable magnetization manipulation by an electric field.

This would pave the way towards magnetoelectric-MRAM devices containing an artificial multiferroic film stack with low power consumption and high switching reliability