Two-dimensional (2D) materials with intrinsic room-temperature ferromagnetism have gathered tremendous interest as promising candidates for next-generation spintronics. Here, on the basis of first-principles calculations, we report a family of stable 2D iron silicide (FeSi_x) alloys via dimensional reduction of their bulk counterparts. Our results demonstrate that 2D Fe₄Si₂-hex, Fe₄Si₂-orth, Fe₃Si₂, and FeSi₂ nanosheets are lattice-dynamically and thermally stable, confirmed by the calculated phonon spectra and Born–Oppenheimer dynamic simulation up to 1000 K. 2D FeSi_x nanosheets are ferromagnetic metals with estimated Curie temperatures ranging from 547 to 971 K due to strong direct exchange interaction between Fe sites. In addition, the electronic properties of 2D FeSi_x alloys can be maintained on silicon substrates, providing an ideal platform for spintronics applications in the nanoscale.

中文翻译：

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具有室温以上铁磁性的二维硅化铁 (FeSix) 合金

具有固有室温铁磁性的二维 (2D) 材料作为下一代自旋电子学的有前途的候选者引起了极大的兴趣。在这里，基于第一性原理计算，我们通过大块对应物的降维报告了一系列稳定的二维硅化铁 (FeSi _{x ) 合金。}我们的结果表明，二维 Fe ₄ Si ₂ -hex、Fe ₄ Si ₂ -orth、Fe ₃ Si ₂和 FeSi ₂纳米片在晶格动力学和热学上是稳定的，这一点已通过计算的声子光谱和玻恩-奥本海默动力学模拟得到证实1000 K. 二维 FeSi _x纳米片是铁磁金属，由于 Fe 位点之间存在强烈的直接交换相互作用，估计居里温度范围为 547 至 971 K。此外，2D FeSi _x合金的电子特性可以在硅衬底上保持，为纳米尺度的自旋电子学应用提供了理想的平台。