Strain Tunability of Perpendicular Magnetic Anisotropy in van der Waals Ferromagnets VI<sub>3</sub>.

Zhang, Xi; Wang, Le; Su, Huimin; Xia, Xiuquan; Liu, Cai; Lyu, Bingbing; Lin, Junhao; Huang, Mingyuan et al. · Nano Lett · 2022

basic_science · Level V

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Abstract

Layered ferromagnets with strong magnetic anisotropy energy (MAE) have special applications in nanoscale memory elements in electronic circuits. Here, we report a strain tunability of perpendicular magnetic anisotropy in van der Waals (vdW) ferromagnets VI<sub>3</sub> using magnetic circular dichroism measurements. For an unstrained flake, the <i>M</i>-<i>H</i> curve shows a rectangular-shaped hysteresis loop with a large coercivity (1.775 T at 10 K) and remanent magnetization. Furthermore, the coercivity can be enhanced to a maximum of 2.6 T under a 3.8% external in-plane tensile strain. Our DFT calculations show that the increased MAE under strain contributes to the enhancement of coercivity. Meanwhile, the strain tunability on the coercivity of CrI<sub>3</sub>, with a similar crystal structure, is limited. The main reason is the strong spin-orbit coupling in V<sup>3+</sup> in VI<sub>6</sub> octahedra in comparison with that in Cr<sup>3+</sup>. The strain tunability of coercivity in VI<sub>3</sub> flakes highlights its potential for integration into vdW heterostructures.