论文标题
NB掺杂的srtio $ _ \ textbf {3} $（001）表面上的小极极构造
Small Polaron Formation on the Nb-doped SrTiO$_\textbf{3}$(001) Surface
论文作者
论文摘要
立方的钙透明钛钛酸盐Srtio $ _3 $（STO）是研究最多，两极分化的过渡金属氧化物之一。当将多余的电荷引入该材料时，例如，通过掺杂或原子缺陷，Sto倾向于托管极性粒子：由多余的电荷载体与晶体声子场偶联而形成的准粒子。它们的存在改变了材料的特性，并且是许多应用的关键。考虑到极地在表面或附近优先形成，我们通过密度功能理论计算研究了tio $ _2 $ tio $ _2 $终止的小极性形成。我们对NB掺杂和未掺杂的STO（001）表面的几个超级电池板进行建模，并考虑到最近观察到的tio $ _2 $ _2 $终止的表面托管SR-Adatoms。我们的发现表明，小极地在低浓度的NB掺杂时变得稳定，类似于散装中的极性子。此外，我们检查了不同极性构型相对于NB和SR障碍的稳定性，并讨论其光谱特性。
The cubic perovsike strontium titanate SrTiO$_3$ (STO) is one of the most studied, polarizable transition metal oxides. When excess charge is introduced to this material, e.g., through doping or atomic defects, STO tends to host polarons: Quasi-particles formed by excess charge carriers coupling with the crystal phonon field. Their presence alters the materials properties, and is a key for many applications. Considering that polarons form preferentially on or near surfaces, we study small polaron formation at the TiO$_2$ termination of the STO(001) surface via density functional theory calculations. We model several supercell slabs of Nb-doped and undoped STO(001) surfaces with increasing size, also considering the recently observed as-cleaved TiO$_2$ terminated surface hosting Sr-adatoms. Our findings suggest that small polarons become less stable at low concentrations of Nb-doping, in analogy with polarons localized in the bulk. Further, we inspect the stability of different polaron configurations with respect to Nb- and Sr-impurities, and discuss their spectroscopic properties.
