Full 180° Magnetization Reversal with Electric Fields

Achieving 180 degrees magnetization reversal with an electric field rather than a current or magnetic field is a fundamental challenge and represents a technological breakthrough towards new memory cell designs. Here we propose a mesoscale morphological engineering approach to accomplishing full 180 degrees magnetization reversals with electric fields by utilizing both the in-plane piezostrains and magnetic shape anisotropy of a multiferroic heterostructure. Using phase-field simulations, we examined a patterned single-domain nanomagnet with four-fold magnetic axis on a ferroelectric layer with electric-field-induced uniaxial strains. We demonstrated that the uniaxial piezostrains, if non-collinear to the magnetic easy axis of the nanomagnet at certain angles, induce two successive, deterministic 90 degrees magnetization rotations, thereby leading to full 180 degrees magnetization reversals.