论文标题
赤铁矿最薄的极限
Hematite at its thinnest limit
论文作者
论文摘要
由最近合成的二维$α$ -FE $ _2 $ o $ _3 $ [BALAN $ et $ $ al。$ nat的动机。纳米技术。 13，602（2018）]，我们分析了单层和几层$α$ -fe $ _2 $ _2 $ o $ $ _3 $的结构，振动，电子和磁性，相比之下，$ ab-initio $和蒙特 - 卡洛模拟。我们揭示单层$α$ -FE $ _2 $ o $ _3 $（Hematene）如何与几层结构区分开，以及它们与可观察的拉曼光谱之间的不同之处。当$α$ -fe $ _2 $ o $ _3 $变细到单层时，光谱显示出显着峰向更高能量的逐渐变化，以及较低能量的其他功能。光学和电子特性均具有强旋不对称性，这意味着单旋态允许较低能源的光学和电子活动。最后，我们对磁性特性的考虑表明，2D赤铁矿具有所有厚度的抗铁磁基态，但是Morin转变的临界温度随着样品厚度的降低而增加。在所有帐户上，都链接了可用的实验数据，并提示了进一步的测量。
Motivated by the recent synthesis of two-dimensional $α$-Fe$_2$O$_3$ [Balan $et$ $al.$ Nat. Nanotech. 13, 602 (2018)], we analyze the structural, vibrational, electronic and magnetic properties of single- and few-layer $α$-Fe$_2$O$_3$ compared to bulk, by $ab-initio$ and Monte-Carlo simulations. We reveal how monolayer $α$-Fe$_2$O$_3$ (hematene) can be distinguished from the few-layer structures, and how they all differ from bulk through observable Raman spectra. The optical spectra exhibit gradual shift of the prominent peak to higher energy, as well as additional features at lower energy when $α$-Fe$_2$O$_3$ is thinned down to a monolayer. Both optical and electronic properties have strong spin asymmetry, meaning that lower-energy optical and electronic activities are allowed for the single-spin state. Finally, our considerations of magnetic properties reveal that 2D hematite has anti-ferromagnetic ground state for all thicknesses, but the critical temperature for Morin transition increases with decreasing sample thickness. On all accounts, the link to available experimental data is made, and further measurements are prompted.
