论文标题
在Ultrathin（Lanio $ _ {3-δ} $）中调整载体本地化，磁性和热电属性（LANIO $ _ {3-δ} $）$ _ 1 $/（LAALO $ _ {3} $）$ _ 1 $（001）
Tuning of the carrier localization, magnetic and thermoelectric properties in ultrathin (LaNiO$_{3-δ}$)$_1$/(LaAlO$_{3}$)$_1$(001) superlattices by oxygen vacancies
论文作者
论文摘要
使用密度功能理论计算与现场库仑排斥项（DFT+$ u $）和玻尔兹曼运输理论的结合，我们在恒定的放松时间近似中探索了氧气空位对超平稳性能的氧气空位对电子，磁性和热电学性能的影响。 （lanio $ _ {3-δ} $）$ _ 1 $/（laalo $ _ {3} $）$ _ 1 $（001）超级晶格（SLS）。对于原始SL，是一种反铁磁性电荷 - 配置（AFM-CD）（$ d^{8} $ {$ {$ \ \ \ \ usewises L $} $^{2} $）$ _ {s = 0} $（$ d^{8} $ _ {8} $ _ {s = 1} $ _ {s = 1} $ apeplip stain carpective stagips stagips stagipection carpective。在$δ$ = 0.125和0.25时，从Nio $ _ {2} $ plane中从氧缺陷中释放出的电子定位触发了一种电荷 - 触发物质，从而导致$ a _ {\ Mathrm {sto {sto}} $（tensile} $（tensile clantial and tensile clantial and a $ a） $ a _ {\ mathrm {lsao}} $（压缩）。在$δ$ = 0.5时，出现了一个绝缘阶段，其交替条纹Ni $^{2+} $（高旋转）和Ni $^{2+} $（低旋转）以及沿[110]方向（S-AFM）订购的氧空位，而不受应变的不利。这会导致$ n $ type的平面电源因子为24〜 $ $ w/k $^2 $^2 $ cm $ a _ _ _ {\ mathrm {sTo}} $和14〜 $ $ $ w/k $^2 $ cm，$ a _ {此外，原始和$δ$ = 0.5 sls显示为动态稳定。这证明了通过氧空位的超薄镍超晶格的电子，磁性和热电性能的微调。
Using a combination of density functional theory calculations with an on-site Coulomb repulsion term (DFT+$U$) and Boltzmann transport theory within the constant relaxation time approximation, we explore the effect of oxygen vacancies on the electronic, magnetic, and thermoelectric properties in ultrathin (LaNiO$_{3-δ}$)$_1$/(LaAlO$_{3}$)$_1$(001) superlattices (SLs). For the pristine SL, an antiferromagnetic charge-disproportionated (AFM-CD) ($d^{8}${$\underline L$}$^{2}$)$_{S=0}$($d^{8}$)$_{S=1}$ phase is stabilized, irrespective of strain. At $δ$ = 0.125 and 0.25, the localization of electrons released from the oxygen defects in the NiO$_{2}$ plane triggers a charge-disproportionation, leading to a ferrimagnetic insulator both at $a_{\mathrm{STO}}$ (tensile strain) and $a_{\mathrm{LSAO}}$ (compressive strain). At $δ$ = 0.5, an insulating phase emerges with alternating stripes of Ni$^{2+}$ (high-spin) and Ni$^{2+}$ (low-spin) and oxygen vacancies ordered along the [110] direction (S-AFM), irrespective of strain. This results in a robust $n$-type in-plane power factor of 24~$μ$W/K$^2$ cm at $a_{\mathrm{STO}}$ and 14~$μ$W/K$^2$ cm at $a_{\mathrm{LSAO}}$ at 300~K (assuming relaxation time $τ= 4$~fs). Additionally, the pristine and $δ$ = 0.5 SLs are shown to be dynamically stable. This demonstrates the fine tunability of electronic, magnetic, and thermoelectric properties of ultrathin nickelate superlattices by oxygen vacancies.
