Voltage-controlled three-state magnetic memory based on anisotropic magnetoresistance in a multiferroic heterostructure.

An energy efficient technique has shown to produce a three-state magnetic memory cell in a [011]-poled Ni80Co20/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) heterostructure. Via the magnetic field deposition, a 45 magnetic easy axis of the NiCo film was induced in the film plane. By using a strong converse magnetoelectric coupling between the NiCo film and the PMN-PT, the magnetic moments of NiCo can be modulated to [001] and [1-10] directions of PMN-PT by selecting an appropriate electric field (E-field). Consequently, large, medium, and small anisotropic magnetoresistance (AMR) values are obtained by fixing a measuring current along the [001] direction. The required E-field significantly reduces due to the initial direction of NiCo along the 45 direction. The tunability of the AMR ratio is as large as 87%. These results indicate that an energy efficient approach to generate magnetic storage by using only a small E-field rather than a magnetic field with a high energy consumption was realized. This work shows great potential for the development of ultra-low power and high-density magnetoresistive memory devices. [ABSTRACT FROM AUTHOR]