Control of magnetic anisotropy in epitaxial Co2MnAl thin films through piezo-voltage-induced strain

Abstract

The voltage-controlled magnetic anisotropy of various magnetic materials is an effective method to realize the electronic devices with low power consumption. Here, we investigated the magnetic properties in Co2MnAl/GaAs heterostructures controlled by piezo voltages-induced strain using the magneto-optical Kerr effect microscopy. The coexistence of the in-plane cubic and uniaxial magnetic anisotropies was observed in the initial state of Co2MnAl thin films. The magnetic anisotropy was manipulated effectively by the piezo voltages. The two-step magnetic hysteresis loop measured along the [1−10] direction was changed into a square loop when the piezo voltage was −30 V (compressed state). On the contrary, the loop of the [110] direction was changed into a two-step loop. The loops of [100] and [010] axes represented the hard axes and were almost unchanged with the piezo voltages. We found that the transformations of loops in [110] and [1−10] axes were manipulated by the piezo voltage induced additional uniaxial anisotropy. Finally, we demonstrated that the planar Hall resistance (RH) in the Hall device can be effectively controlled by the piezo voltages. Our study identified that the voltage controlled room temperature magnetic devices through strain engineering could have great potential for spintronic applications.

Structural characterization and electronic properties of Ni/rubrene bilayers with alternative stacking sequences

“…In order to understand the significance of the interface in the global magnetic hysteresis, we considered an IP-hysteresis recorded at room temperature to determine the magnetic anisotropy of the specimens. The effective uniaxial (K eff u ) and cubic (K eff c ) anisotropy constants can be expressed as 63,64…”

“…In order to understand the significance of the interface in the global magnetic hysteresis, we considered an IP-hysteresis recorded at room temperature to determine the magnetic anisotropy of the specimens. The effective uniaxial ( K eff u ) and cubic ( K eff c ) anisotropy constants can be expressed as 63,64 where K eff u is the effective uniaxial anisotropy, K eff c is the effective cubic anisotropy, H s is the saturation magnetic field, and k is the slope of the hysteresis loop between − H s and + H s . The values of M s , k , K eff u , and K eff c for Ni/Si, rubrene/Ni/Si, and Ni/rubrene/Si are presented in Table 2.…”

Dual-axis control of magnetic anisotropy in a single crystal Co2MnSi thin film through piezo-voltage-induced strain

“…To date, there have been multiple types of electrical manipulation ways of the magnetization rotation or magnetic anisotropy variation, such as spin-orbit torque (SOT), [1][2][3][4][5][6][7] spin transfer torque (STT), [8][9][10][11] magneto-electrical coupling (MEC) effect, [12][13][14][15][16][17] and strain. [18][19][20][21][22][23][24][25] The piezo-voltage-induced strain, as a way of voltage-controlled magnetic anisotropy (VCMA), has attracted the attention of many researchers due to the performance of low-power consumption. 22,25 The main studies of strain controlled magnetization are related to the inverse piezoelectric effect of piezoelectric materials in the ferromagnetic/piezoelectric heterostructure.…”

“…23 However, the previous relative studies of straincontrolled magnetization rotation were mainly demonstrated in a uniaxial regulation manner. [22][23][24]26 The stress regulation characteristic disappears or weakens when the specic crystal orientation of magnetic thin lms rotates relative to the stress axis. This problem would be effectively avoided by realizing dual-axis or multi-axis stress-regulated magnetization rotation.…”

Magnetoelastic interactions and magnetic damping in Co2Fe0.4Mn0.6Si and Co2FeGa0.5Ge0.5 Heusler alloys thin films for spintronic applications

“…The magnetoelastic part of magnetic anisotropy in Co 2 FeAl films was studied by Belmeguenai et al 66 , 67 . The effects connected with piezoelectric strain were studied in Co 2 FeAl 68 and Co 2 MnAl 69 . The changes in magnetic anisotropy associated with strain-induced tetragonal lattice distortion in Co 2 MnSi and Co 2 FeSi thin films were investigated by Pandey et al 70 , nevertheless, this approach neglected the presence of surface effects.…”