论文标题
预测很少的原子层极性钙钛矿的结构，电子和磁性
Predicting the Structural, Electronic and Magnetic Properties of Few Atomic-layer Polar Perovskite
论文作者
论文摘要
进行密度函数理论（DFT）计算以预测电气中性或带电的少数原子层（Al）氧化物的结构，电子和磁性，其母体系统基于极性钙钛矿$ KTAO_ {3} $。它们的属性随ALS（$ n_ {al} $）和化学计量比的数量而异。在几个限制（$ n_ {al} \ leqslant 14 $）中，具有化学公式$ $（ktao_ {3}）_ {n} $的偶数Al（el）系统是半导体，而奇数Al（ol（OL）系统具有formula（$ k_ {$ k_ {n+1}} $ k_ {n} ta_ {n+1} o_ {3n+2} $）是半米，除了唯一的$ kta_ {2} o_ {5} $ case，这是由于大型peierls扭曲而导致的半导体。在达到一定的临界厚度（$ n_ {al}> 14 $）之后，EL系统显示了铁磁表面状态，而铁磁磁性在OL系统中消失了。在接近二维（2D）极限时极性钙钛矿的基本复杂性的预测可能有助于解释实验观察结果。
Density functional theory (DFT) calculations are performed to predict the structural, electronic and magnetic properties of electrically neutral or charged few-atomic-layer (AL) oxides whose parent systems are based on polar perovskite $KTaO_{3}$. Their properties vary greatly with the number of ALs ($n_{AL}$) and the stoichiometric ratio. In the few-AL limit ($n_{AL}\leqslant 14$), the even AL (EL) systems with chemical formula $(KTaO_{3})_{n}$ are semiconductors, while the odd AL (OL) systems with formula ($K_{n+1}Ta_{n}O_{3n+1}$ or $K_{n}Ta_{n+1}O_{3n+2}$) are half-metal except for the unique $KTa_{2}O_{5}$ case which is a semiconductor due to the large Peierls distortions. After reaching certain critical thickness ($n_{AL}>14$), the EL systems show ferromagnetic surface states, while ferromagnetism disappears in the OL systems. These predictions from fundamental complexity of polar perovskite when approaching the two-dimensional (2D) limit may be helpful for interpreting experimental observations later.
