Suppressing Thermal Conductivity in SrTiO 3 by Introducing Oxygen Isotope Disorder

作者：Yipeng Zang, Zhiming Geng, Di Chen, Ningchong Zheng, Xinwei Fang, Xuejun Yan, Zhengbin Gu, Pol Torres, Jorge Íñiguez, Rong Huang, Fangsen Li, Riccardo Rurali, Yan‐Feng Chen, Xiaoqing Pan, Ming‐Hui Lu, Shouguo Wang, Yuefeng Nie · 发表于：The Journal of Physical Chemistry Letters · 年份：2025 · DOI：10.1021/acs.jpclett.4c03034 · 被引用次数：5 · 研究领域：Electronic and Structural Properties of Oxides、Ferroelectric and Piezoelectric Materials、Magnetic and transport properties of perovskites and related materials

Transition metal oxides are promising candidates in the field of thermoelectricity, which can convert heat and electricity into each other and realize the efficient utilization of waste energy. For the figure of merit ZT = S 2 σ T /(κ e + κ l ), a lower thermal conductivity is desired for an enhanced ZT, and cation doping is an appropriate way to regulate the thermal transport properties. However, because S, σ, and κ e are strongly coupled with each other, cation doping for one parameter modification can generate compensation with others, making regulation more difficult. In this work, we demonstrate the effective engineering of the thermal conductivity of SrTiO 3 films by partial oxygen isotope substitution with 18 O using a straightforward aftergrowth thermal annealing process. The results show that the isotope disorder promotes the scattering of phonons and generates a nearly 20% decreased thermal conductivity of SrTiO 3 films. Our work provides a convenient new route for the design of thermoelectric materials with high ZT values.