Full voltage manipulation of the resistance of a magnetic tunnel junction

Abstract

One of the motivations for multiferroics research is to find an energy-efficient solution to spintronic applications, such as the solely electrical control of magnetic tunnel junctions. Here, we integrate spintronics and multiferroics by depositing MgO-based magnetic tunnel junctions on ferroelectric substrate. We fabricate two pairs of electrodes on the ferroelectric substrate to generate localized strain by applying voltage. This voltage-generated localized strain has the ability to modify the magnetic anisotropy of the free layer effectively. By sequentially applying voltages to these two pairs of electrodes, we successively and unidirectionally rotate the magnetization of the free layer in the magnetic tunnel junctions to complete reversible 180° magnetization switching. Thus, we accomplish a giant nonvolatile solely electrical switchable high/low resistance in magnetic tunnel junctions at room temperature without the aid of a magnetic field. Our results are important for exploring voltage control of magnetism and low-power spintronic devices.

Electric-field-assisted non-volatile magnetic switching in a magnetoelectronic hybrid structure

“…Naturally, the magnetic states of the FL should be responsible for the TMR response to the E- and H-fields in the hybrid device (see details in Figure S7 in the supplemental information ). Therefore, the CTC results again demonstrate that E-field-induced magnetoelastic anisotropy is the primary contributor over the magnetic anisotropy rotation and the relative magnetization orientation of the FL with respect to the RL ( Chen et al., 2019b , 2019c ).…”

“…Figure 1 B shows the layered sequence of the MTJ stack, including the FL and RL components. The Ta/Ru/Ta/CoFe/IrMn assembly serves as the top electrode, and the Au layer below the PMN-PT serves as the bottom electrode for the applied E-fields, saving the top MTJ ovals from the potential damage as a result of the E-field ( Wang et al., 2012 ; Chen et al., 2019c ). The length of the MTJ ovals is along the in-plane [100] direction of the PMN-PT substrate.…”

“…Thus, a slim, narrow, and gradual TC loop, rather than a slanted loop, is observed, as previously shown in Figure 3, even though the E-field was increased to 6 kV/cm. This (Zhao et al, 2016;Chen et al, 2019c), who showed efficient strain transfer and slanted TC loops in thinner MTJ/(001)-PMN-PT hybrids ($24 nm and $27 nm, respectively) along the major axis of the MTJs. Therefore, angular magnetic switching should result from competition among the magnetic shape anisotropy, the E-field-induced magnetoelastic anisotropy, and the external Zeeman energy in the FL (Zhao et al, 2018b;Chen et al, 2016).…”

“…Two local gating configurations were applied to produce anisotropic strain from the isotropic FE layer in affecting magnetization switching, which in this work is volatile once the E-field is removed. Overall, few experimental works have been available on E-field controlled MTJ/FE hybrids ( Li et al., 2014 ; Chen et al., 2019b , 2019c ; Zhao et al., 2016 ). The integration of spintronic and FE components remains a challenging task ( Heron et al., 2014 ; Yang et al., 2014 ).…”

Proposal for an input interface and multi‐output structures of all‐spin logic circuits based on magnetic tunnel junction

“…1, the aspect ratio of the fixed layer in MTJ is smaller than that of the free layer, which is not conducive to maintaining the fixed magnetisation when current is applied. In order to ensure that the magnetisation direction of the fixed layer does not change, an antiferromagnetic IrMn layer can be placed on the fixed layer to pin the fixed layer [27].…”