Two-dimensional (2D) ferromagnets with high spin-polarization ratio and high Curie temperature are crucial for developing next-generation spintronic nanodevices. Using first-principles calculations, we predict two polymorphic modifications (t-VN and h-VN) of 2D VN lattices that have robust intrinsic ferromagnetic properties and high Curie temperatures. Whereas t-VN has 99.9% of spin polarization at the Fermi level, h-VN possesses a half-metallic type of conductivity and keeps it after contact with semiconducting MoS₂, which can be used as the substrate for h-VN synthesis and valley polarized contacts. Magnetocrystalline anisotropy energy of 2D VN polymorphs is found to be at least an order larger than those of Fe and Ni bulks. The phonon spectra and ab initio molecular dynamic simulation prove that 2D VN lattices have a high thermodynamic stability. These advantages demonstrate that the VN monolayers should be promising candidates for low-dimensional spintronic devices.

中文翻译：

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VN的二维晶格：纳米尺度上铁磁性和半金属的出现

具有高自旋极化率和高居里温度的二维（2D）铁磁体对于开发下一代自旋电子纳米器件至关重要。使用第一性原理计算，我们预测了二维VN晶格的两个多态修饰（t -VN和h -VN），它们具有强大的固有铁磁特性和居里温度高。而吨-VN具有自旋极化为99.9％，在费米能级，ħ -VN具有半金属型导电性，并与半导体的MoS接触之后保持它₂，其可被用作衬底为ħ-VN合成和谷极极化接触。发现2D VN多晶型的磁晶各向异性能至少比Fe和Ni块的磁晶各向异性能大一个数量级。声子光谱和从头算分子动力学模拟证明了二维VN晶格具有很高的热力学稳定性。这些优点表明，VN单层应该是低维自旋电子器件的有前途的候选者。