Interplay of point defects, biaxial strain, and thermal conductivity in homoepitaxial SrTiO3 thin films
Interplay of point defects, biaxial strain, and thermal conductivity in homoepitaxial SrTiO3 thin films
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DOI：
10.1063/1.3682300
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发表时间：
2012-02
影响因子：
4
通讯作者：
S. Wiedigen;T. Kramer;M. Feuchter;I. Knorr;N. Nee;J. Hoffmann;M. Kamlah;C. Volkert;C. Jooss
中科院分区：
文献类型：
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作者：
S. Wiedigen;T. Kramer;M. Feuchter;I. Knorr;N. Nee;J. Hoffmann;M. Kamlah;C. Volkert;C. Jooss
区分点缺陷和晶格应变对热导率的影响是提高钛酸锶热电性能的关键。研究了离子束溅射制备的同质外延钛酸锶薄膜中沉积过程中产生的缺陷、诱导晶格应变及其对热导率κ的影响之间的关系。降低沉积温度可通过提高点缺陷密度引起晶格膨胀，从而提高薄膜的硬度。由于衬底-薄膜的完全共格界面，晶格失配导致了很大的双轴应变。然而，我们可以发现κ的温度依赖关系主要是对缺陷浓度敏感的。
Separating out effects of point defects and lattice strain on thermal conductivity is essential for improvement of thermoelectric properties of SrTiO3. We study relations between defects generated during deposition, induced lattice strain, and their impact on thermal conductivity κ in homoepitaxial SrTiO3 films prepared by ion-beam sputtering. Lowering the deposition temperature gives rise to lattice expansion by enhancement of point defect density which increases the hardness of the films. Due to a fully coherent substrate-film interface, the lattice misfit induces a large biaxial strain. However, we can show that the temperature dependence of κ is mainly sensitive on the defect concentration.