Strain-Mediated Magnetization Switching Behavior in a Bicomponent Nanomagnet

Abstract

The strain-mediated method is considered to be a promising solution for implementing energy-efficient magnetization rotation. However, current methods strictly require a voltage clock. Here, a multiferroic nanomagnet composed of bicomponent magnetic materials (Terfenol-D:$\mathrm{Ni}$ = 1:2) is developed to study strain-mediated magnetization switching behavior. With micromagnetic simulations, what is demonstrated is that the strict requirements for a precise applied voltage period can be overcome in such a bicomponent nanomagnet, where the threshold of the square-wave voltage pulse width required for complete and repeated magnetization reversal is only 0.42 ns if the amplitude of the voltage is 1 V. Besides deterministic magnetization switching, further study shows that the unique strain-mediated stochastic magnetization reversal behavior of the designed device can be used to mimic the biological neuron. With the application of the derived neural device parameters, a three-layer artificial neural network is further constructed to recognize a handwritten dataset, based on which, an accuracy of more than 98% can be achieved. Overall, these results open an intriguing way toward straintronic memory and neuromorphic systems.