Investigation of magneto-electric effects in (PMN-PT) @ NiFe2O4 core shell nanostructures and nanocomposites for non volatile memory applications

Abstract

We studied structural, ferroelectric, magnetic and magneto-electric (ME) properties of (0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3) (PMN-PT)/NiFe2O4 nanocomposite and core shell nanostructures (with ferrimagnetic NiFe2O4 core and ferroelectric PMN-PT shell). Morphology of core shell nanostructures and nanocomposites have been analyzed using transmission electron microscopy and scanning electron microscopy. Both the (PMN-PT)/NiFe2O4 samples reveal magneto electric effect at room temperature. The ME coupling coefficient (α) was found to be two order of magnitude higher for (PMN-PT)/NiFe2O4 nanocomposites in comparison to the core shell nanostructures. The PMN-PT/NiFe2O4 nano composite showed repeatable and reversible switching of α (α > 0 and α < 0) in response to the applied positive and negative electric-pulses E = 20 kV/cm. The response of α was recorded for eighteen cycles of electric pulses (single pulse duration = 100 s). The binary information can be stored in two states of α (α > 0 and α < 0) in non volatile manner. The PMN-PT/NiFe2O4 nanocomposite exhibited retention of α for ~104 s and hence it can be used for non volatile memory applications. The principle of using α for memory storage may offer numerous benefits such as low power consumption, avoid destructive reading process, and easy writing/reading process.