Thermoelectric phase diagram of the SrTiO3–SrNbO3 solid solution system
Thermoelectric phase diagram of the SrTiO3–SrNbO3 solid solution system
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DOI：
10.1063/1.4983359
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发表时间：
2017-04
影响因子：
3.2
通讯作者：
Yu-qiao Zhang;B. Feng;Hiroyuki Hayashi;T. Tohei;I. Tanaka;Y. Ikuhara;H. Ohta
中科院分区：
文献类型：
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作者：
Yu-qiao Zhang;B. Feng;Hiroyuki Hayashi;T. Tohei;I. Tanaka;Y. Ikuhara;H. Ohta
在这里，我们给出了SrTi1−xNbxO3（0.05≤x≤1）固溶体体系的热电相图，这是我们从外延薄膜的表征中得出的。我们在系统中观察到两个热电相边界，它们源于载流子有效质量在x ~ 0.3处的阶梯状下降和载流子弛豫时间在x ~ 0.5处的局部最小值。这些相边界的起源被认为与等价/杂价b位取代有关：在x 0.3的组合物中，抛物型Ti 3d轨道主导电子传导。在x ~ 0.5时，晶格的四方畸变，其中b位由Ti4+和Nb4+离子组成，导致形成尾巴状杂质带，使电子散射最大化。这些结果为进一步研究提高SrTi1−xNbxO3的热电性能奠定了基础。
Here, we present a thermoelectric phase diagram for the SrTi1−xNbxO3 (0.05 ≤ x ≤ 1) solid solution system, which we derived from the characterization of epitaxial films. We observed two thermoelectric phase boundaries in the system, which originate from the step-like decrease in carrier effective mass at x ∼ 0.3 and from a local minimum in carrier relaxation time at x ∼ 0.5. The origins of these phase boundaries are considered to be related to isovalent/heterovalent B-site substitution: parabolic Ti 3d orbitals dominate electron conduction for compositions with x 0.3. At x ∼ 0.5, a tetragonal distortion of the lattice, in which the B-site is composed of Ti4+ and Nb4+ ions, leads to the formation of tail-like impurity bands, which maximizes the electron scattering. These results provide a foundation for further research into improving the thermoelectric performance of SrTi1−xNbxO3.