Abstract The modification upon Sb doping on Ba-site of YBa2-xSbxCu3O7-δ superconductor on its electronic behaviour has been studied by applying the Density Functional Theory (DFT) via first principle study. The properties were investigated via computational simulation adopting CASTEP computational code. The crystal structure was constructed and calculated using Visual Crystal Approximation (VCA) with Generalized Gradient Approximation Perdew Burke Ernzerhof (GGA PBE) exchange–correlation and ultrasoft pseudopotential. Geometry optimization at 4 × 4 × 1 k-point sampling shown energy converged at 400 eV. Computer simulation was used to determine the electronic modifications occurred between the CuO chain and CuO2 plane with Ba-site of Sb dopant. Generally, the YBa2-xSbxCu3O7-δ has orthorhombic crystal structure since the lattice parameters of a, b, and c are not the same. From the band structure analysis, the smallest bandgap was observed at x = 0.225 between its upper conduction (CV) and the lower valence band (VB). The electrons were found to be more concentrated towards the Fermi level when observed via its density of state distribution. In the electron density differences images, we can observe the merge of orbital configuration contributed by each atom upon doping at x = 0.225. From there we can say that on that Sb concentration, the YBa2-xSbxCu3O7- is optimum.

中文翻译：

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使用密度泛函理论研究 Sb 掺杂的 YBa2-xSbxCu3O7-δ 超导体对电子行为的影响

摘要 应用密度泛函理论(DFT)，通过第一性原理研究，研究了YBa2-xSbxCu3O7-δ超导体Ba位掺杂Sb对其电子行为的改变。通过采用CASTEP计算代码的计算模拟来研究这些特性。使用具有广义梯度近似 Perdew Burke Ernzerhof (GGA PBE) 交换相关和超软赝势的视觉晶体近似 (VCA) 构建和计算晶体结构。4 × 4 × 1 k 点采样的几何优化显示能量收敛于 400 eV。计算机模拟被用来确定在 CuO 链和 CuO2 平面之间发生的电子修饰，带有 Sb 掺杂剂的 Ba 位点。通常，YBa2-xSbxCu3O7-δ 具有正交晶体结构，因为 a、b、和 c 不一样。根据能带结构分析，在其上导带 (CV) 和下价带 (VB) 之间的 x = 0.225 处观察到最小带隙。当通过状态分布密度观察时，发现电子更集中于费米能级。在电子密度差异图像中，我们可以观察到每个原子在 x = 0.225 处掺杂时贡献的轨道构型的合并。从那里我们可以说在那个 Sb 浓度下，YBa2-xSbxCu3O7- 是最佳的。在电子密度差异图像中，我们可以观察到每个原子在 x = 0.225 处掺杂时贡献的轨道构型的合并。从那里我们可以说在那个 Sb 浓度下，YBa2-xSbxCu3O7- 是最佳的。在电子密度差异图像中，我们可以观察到每个原子在 x = 0.225 处掺杂时贡献的轨道构型的合并。从那里我们可以说在那个 Sb 浓度下，YBa2-xSbxCu3O7- 是最佳的。