Critical evaluation of the colossal Seebeck coefficient of nanostructured rutile MnO2
Critical evaluation of the colossal Seebeck coefficient of nanostructured rutile MnO2
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DOI：
10.1088/0953-8984/27/11/115302
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发表时间：
2015-03
期刊：
影响因子：
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通讯作者：
D. Music;J. Schneider
中科院分区：
文献类型：
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作者：
D. Music;J. Schneider
利用密度泛函理论对文献数据中的三个数量级散射进行了批判性评价，探讨了纳米结构金红石型MnO 2的Seebeck系数与电子结构之间的相关性。我们的假设是，在纳米尺度上的微观结构和形态是导致这种行为，我们已经测试通过比较塞贝克系数的散装二氧化锰与两个低能量的表面：二氧化锰（1 1 0）和二氧化锰（0 0 1）。从这些数据中可以明显看出，通过影响纳米尺度上的畴尺寸和纹理，可以获得塞贝克系数两个数量级以上的变化。这可以通过分析电子结构来理解。表面杂化Mn d-O p态填充了MnO 2的带隙，从而大大改变了其输运性质。
We have explored the correlation between the Seebeck coefficient and the electronic structure of nanostructured rutile MnO2 using density functional theory to critically appraise the three orders of magnitude scatter in literature data. Our hypothesis is that the microstructure and morphology on the nanoscale is causing this behaviour, which we have tested by comparing the Seebeck coefficient of bulk MnO2 with two low-energy surfaces: MnO2(1 1 0) and MnO2(0 0 1). From these data, it is evident that variations over two orders of magnitude in the Seebeck coefficient can be attained by affecting domain size and texture on the nanoscale. This may be understood by analysing the electronic structure. Surface hybridized Mn d–O p states fill the band gap of MnO2 and thus substantially alter the transport properties.