论文标题
改善（1-X）LACOO3/（x）LA0.7SR0.3COO3复合材料中的热电特性改进
Improved Thermoelectric Properties in (1-x)LaCoO3/(x)La0.7Sr0.3CoO3 Composite
论文作者
论文摘要
需要高较高的Seebeck系数，较大的电导率（σ）和降低的导热率（κ）才能在理想的热电（TE）系统中实现高分子（ZT），这在单个系统中由于TE参数的相互依赖性而在单个系统中具有挑战性。复合方法有望操纵TE参数。在这项研究中，讨论了（1-x）lacoo3/（x）La0.7Sr0.3COO3（0.00 \ leq x \ leq 0.05）的TE性能。结构分析证实了复合材料中的各个相，电子显微镜分析进一步支持。 X射线光电子分析表明，Parent Lacoo3系统中存在氧空位（VO），并随着复合材料中的LA0.7SR0.3COO3（LSCO）的添加而增加。 VO的增加提高了钴的退化状态，因此在复合材料中改善了S。 S和σ的温度变化与自旋状态过渡一致，并显示了这两个参数之间的相关性。通过在复合材料中添加球磨球LA0.7SR0.3COO的κ和σ的降低分别归因于增强的声子和荷载载流子散射。与在800 K处的Parent Lacoo3系统相比，增强S和减少κ}的协同作用可改善复合材料的ZT五倍。此方法还可以改善基于LACOO3的系统的工作温度。
A high Seebeck coefficient (S), large electrical conductivity (σ), and reduced thermal conductivity (κ) are required to achieve a high figure-of-merit (zT) in an ideal thermoelectric (TE) system, which is challenging in a single system due to the interdependence of TE parameters. Composite approach is promising to manipulate the TE parameters. In this study, TE properties of (1-x)LaCoO3/(x)La0.7Sr0.3CoO3 (0.00 \leq x \leq 0.05) composite is discussed. The structural analysis confirms individual phases in the composite, which is further supported by electron microscopy analysis. The x-ray photoelectron analysis indicates that oxygen vacancies (VO) are present in the parent LaCoO3 system and increase with the addition of La0.7Sr0.3CoO3 (LSCO) in the composite. The increase in VO raises the degenerate states of cobalt and hence improves S in the composites. Temperature variation in S and σ are consistent with the spin-state transition and shows the correlation between these two parameters. The reduction in κ and σ with the addition of ball-milled La0.7Sr0.3CoO3 in the composite is attributed to the enhanced phonon-phonon and charge carrier scattering, respectively. A synergistic effect of enhanced S and reduced κ} result in five times improvement in zT of the composite compared to the parent LaCoO3 system at 800 K. This approach also improves the operating temperature for LaCoO3 based systems.
