Subhan Fazle, Ali Luqman, Shehzad Nasir, Zhou Yanguang, Qin Zhenzhen, Qin Guangzhao
State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, P. R. China.
Department of Pharmacology, University of Virginia, 22903, Charlottesville, VA, USA.
Phys Chem Chem Phys. 2025 Jun 5;27(22):11811-11820. doi: 10.1039/d5cp00648a.
Strain engineering can induce remarkable changes in the intrinsic properties of parent two-dimensional (2D) materials. In this study we perform first-principles calculations to investigate the effects of both tensile and compressive strain on the different properties of a 2D ferromagnetic (FM) van der Waals (vdW) CrI/VI heterostructure material, where the energetically more stable AB stacking is used. Interestingly, tensile strain enhances the FM ground state, while compressive strain reduces the FM properties. Besides, we report a substantial improvement in the magnetic, electronic and valleytronics properties of the vdW CrI/VI heterostructure. Interestingly, the ferromagnetism of the vdW CrI/VI heterostructure remains unchanged under biaxial strain. We also used Monte Carlo simulations to investigate the biaxial strain effect above the Curie temperature. Including spin-orbit coupling (SOC), we found a peculiar change in the band structure. Besides, the SOC effect causes a splitting of bands at the high-symmetry points and ', which results in a large change in the valleytronics but also reduces the band gap of the vdW CrI/VI heterostructure subsequently with biaxial strain. At the end we also investigated the optical properties. Therefore, our findings suggest new design strategies for constructing a FM CrI/VI vdW heterostructure for prominent valleytronics, opto-electronic and spintronic device applications.
应变工程可以在母体二维（2D）材料的本征特性中引发显著变化。在本研究中，我们进行第一性原理计算，以研究拉伸应变和压缩应变对二维铁磁（FM）范德华（vdW）CrI/VI异质结构材料不同性质的影响，其中使用了能量上更稳定的AB堆叠结构。有趣的是，拉伸应变增强了铁磁基态，而压缩应变降低了铁磁性能。此外，我们报告了vdW CrI/VI异质结构在磁、电子和谷电子学性质方面的显著改善。有趣的是，vdW CrI/VI异质结构的铁磁性在双轴应变下保持不变。我们还使用蒙特卡罗模拟研究了居里温度以上的双轴应变效应。包括自旋轨道耦合（SOC）在内，我们发现能带结构发生了奇特的变化。此外，SOC效应导致高对称点 和 '处的能带分裂，这不仅导致谷电子学发生很大变化，而且随后随着双轴应变降低了vdW CrI/VI异质结构的带隙。最后，我们还研究了光学性质。因此，我们的研究结果为构建用于突出谷电子学、光电子和自旋电子器件应用的铁磁CrI/VI vdW异质结构提出了新的设计策略。
