Magnetic and electric polar regions in the magnetoelectric composite microstructure

Magnetoelectric (ME) composites containing lead-free oxides with high dielectric constant and switchable electric polarization are required for use in devices in integrated microelectronics and memory storage. Introduction of random local heterogeneity originally meant to enhance ferroelectric polarization is employed in ME composite to generate ME response through simulation and experiment. Using a combination of continuum simulations, atomic force microscopy, and screen printing of ME composite we demonstrate robust magnetoelectric coupling in environmentally benign lead-free rare earth substituted SrTiOFormula: see text-CoFeFormula: see textOFormula: see text system. Distinct from other reports, the locations of polar magnetic regions (PMRs) and electric regions -that are critical for information storage- in the microstructure are identified in this system. Antiparallel local magnetic field vectors dots the microstructure of the composite. Detection of local stress/strain formations in accordance with magnetostriction is a prime validation of the robustness of computational model. Besides, the computed averages of polarization and magnetization along the applied field direction are found to be in good agreement with the measurements. Histograms of local strains were mapped in order to go incisively into the composite microstructure. Substantial build-up of electrical potential (a measure of the abundance of piezoelectric charges) induced by the external magnetic field is one of the key features observed.