Strain-mediated magnetoelectric control of tunneling magnetoresistance in magnetic tunneling junction/ferroelectric hybrid structures

Abstract

Because of the wide selectivity of ferromagnetic and ferroelectric (FE) components, electric-field (E-field) control of magnetism with via strain mediation can be easily realized through composite multiferroic heterostructures. Here, an MgO-based magnetic tunnel junction (MTJ) is chosen rationally as ferromagnetic constitution and a high-activity (001)-Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-0.3PT) single crystal is selected as FE component to create a multiferroic MTJ/FE hybrid structure. The shape of tunneling magnetoresistance (TMR) vs. in situ E-fields imprints the butterfly loop of piezo-strain of the FE without magnetic field biasing. The E-field-controlled change of the TMR ratio is up to -0.27% without magnetic-field bias. Moreover, when a typical magnetic field (~±10-Oe) is applied along the minor axis of the MTJ, the butterfly loop is changed significantly by E-fields relative to that without magnetic field biasing. This suggests that the E-field-controlled junction resistance is spin-dependent and correlated with magnetization switching in the free layer of the MTJ. In addition, based on such a multiferroic heterostructure, a strain-gauge factor up to approximately 40 is achieved, which decreases further with a sign change from positive to negative with increasing magnetic fields. This multiferroic hybrid structure is a promising avenue to control TMR through E-fields in low-power-consumption spintronic and straintronic devices at room temperature.

Rational design of Bi-doped rGO/Co3O4 nanohybrids for ethanol sensing

“…With the rapid development of Internet of things, various sensor-based techniques are being extensively developed and applied for industry, agriculture, environment control, enhancement of life quality, and safety [1][2][3][4]. Among various types of sensors, chemiresistive gas sensors based on metal oxide semiconductors (MOSCs), such as Co3O4 [5], rGO/Co3O4 [6][7][8], Bi2O3 [9], SnO2 [10], In2O3 [11], and WO3 [12,13], as well as their nanocomposites [14][15][16], have many advantages including good sensitivity, selectivity, stability, cost effectiveness, and simple implementation for real-time control.…”