论文标题
YTIO3中的电子结构和小孔极化子
Electronic Structure and Small Hole Polarons in YTiO3
论文作者
论文摘要
作为具有铁磁有序的典型莫特绝缘子，YTIO3（YTO）在研究强电子相关效应和轨道订购方面具有极大的兴趣。在这里，我们报告了YTO膜的第一个分子束外延（MBE）生长，并结合了电子结构和电荷传输特性的理论和实验表征。讨论了YTO MBE增长的障碍，并提出了克服它们的潜在途径。直流薄膜和散装单晶的直流传输和塞贝克测量值鉴定了p型Arrhenius的传输行为，薄膜中的激活能量约为0.17 eV，这与小孔极性从混合密度功能理论（DFT）计算的小孔极性迁移的能屏障一致。硬X射线光电子光谱测量值（HAXPES）显示，低于费米水平的1.1 eV的下hubbard带（LHB），而从光致发光（PL）测量值确定的Mott-Hubbard带隙〜1.5 eV。这些发现为YTO和相关材料的电子带结构提供了关键的见解。
As a prototypical Mott insulator with ferromagnetic ordering, YTiO3 (YTO) is of great interest in the study of strong electron correlation effects and orbital ordering. Here we report the first molecular beam epitaxy (MBE) growth of YTO films, combined with theoretical and experimental characterization of the electronic structure and charge transport properties. The obstacles of YTO MBE growth are discussed and potential routes to overcome them are proposed. DC transport and Seebeck measurements on thin films and bulk single crystals identify p-type Arrhenius transport behavior, with an activation energy of ~ 0.17 eV in thin films, consistent with the energy barrier for small hole polaron migration from hybrid density functional theory (DFT) calculations. Hard X-ray photoelectron spectroscopy measurements (HAXPES) show the lower Hubbard band (LHB) at 1.1 eV below the Fermi level, whereas a Mott-Hubbard band gap of ~1.5 eV is determined from photoluminescence (PL) measurements. These findings provide critical insight into the electronic band structure of YTO and related materials.
