Electric-field-induced in-plane effective 90° magnetization rotation in Co₂FeAl/PMN-PT structure*

Abstract

The in-plane effective 90° magnetization rotation of Co2FeAl thin film grown on PMN-PT substrate induced by the electric field is investigated at room temperature. The magnetic hysteresis loops under different positive and negative electric fields are obtained, which reveals remanent magnetization can be mediated by the electric field. Moreover, under positive electric fields, the obvious 90° magnetization rotation can be observed, while remanent magnetization is nearly unchanged under negative electric fields. The result is consistent with the electric field dependence of effective magnetic field, which can be attributed to the piezostrain effect in Co2FeAl/PMN-PT structure. In addition, the piezostrain-mediated 90° magnetization rotation can be demonstrated by the result of resonance field changing with electric field in the measurement of ferromagnetic resonance, which is promising for the design of future multiferroic devices.

Non-volatile electric field-mediated magnetic anisotropy in CoZr/ PMN-PT structure

“…When applying electric field on the PMN-PT layer, strong strain or charge effect at the interface of FM and PMN-PT layers can mediate magnetic properties of the adjacent FM layer. Because of strain that is caused by the piezo-electric and electrostrictive effects (attributable to applied electric field) in the FE material (Thiele et al, 2007;Pertsev, 2008;Wang et al, 2014;Zhou et al, 2021), large magnetic response was produced in FM layer, which can lead to a strong ME coupling. Thus, one always observes butterfly-type behavior.…”

Electric-Field Control of Magnetoresistance Behavior in a Conetic Alloy Thin Film/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 Multiferroic Heterostructure

“…Subsequently, the magnetization will rotate from the [100] direction (i.e., e.a. direction; Figure 6A) to the [01 1] direction of the FE layer as shown in Figure 6B, increasing the MR because of the AMR effect (Wang et al, 2019;Yamada et al, 2021;Zhou et al, 2021). Therefore, regardless of whether the magnetic field is along the [100] or [01 1] direction, MR increases after applying the E-fields, which is also illustrated by the dashed arrows in Figures 2A,B.…”

“…Second, comparing the CTC mapping results under different E-fields, the applied electric field makes the contour darker, that is, the MR becomes larger, which is also consistent with the TC measurements. Additionally, the position of the maximal magnetoresistance does not move when the electric field is applied, implying that the direction of E-fieldinduced magnetoelastic anisotropy is exactly along the [01 1] direction, so that the magnetization favors to stay in this direction (Nan et al, 2015;Zhou et al, 2021). According to the above experimental results, we further phenomenologically analyze magnetization rotation through energy competitions among the Zeeman, uniaxial magnetic anisotropic, and magnetoelastic anisotropic energies induced by E-fields in a single-domain mode.…”

“…When applying the E-fields, the magnetization rotates toward the [01 1] direction as shown in Figure 6F owing to the aforementioned strainmediated magnetoelectric coupling. Therefore, the magnetization along the [100] direction of the FE layer is easier to reverse with the assistance of the E-field-induced magnetoelastic anisotropy than that in the absence of E-fields (Yang et al, 2021;Zhou et al, 2021), thus decreasing the switching field (Figure 2D). Moreover, the MR decreases considerably, thereby increasing the MR ratio (Figure 3B).…”

“…Recently, Yu et al (2019) found that the lattice distortion caused by residual compressive strain can induce perpendicular magnetic anisotropy in Co 2 MnAl films. Zhou et al (2021) reported an effective in-plane magnetization 90 °rotation induced by the piezo-strain effect in the Co 2 FeAl/ Pb(Mg 1/3 Nb 2/3 ) 0.7 Ti 0.3 O 3 (PMN-PT) structure. Yamada et al (2021) observed that the presence of the magnetoelastic effect owing to spin-orbit interactions at the epitaxial interface between Co 2 FeSi and ferroelectric BaTiO 3 (001) layers.…”