State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University, 310027, Hangzhou, China.
Center of Electron Microscope, School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, China.
Nat Commun. 2018 Apr 24;9(1):1638. doi: 10.1038/s41467-018-04113-y.
For many decades, zero thermal expansion materials have been the focus of numerous investigations because of their intriguing physical properties and potential applications in high-precision instruments. Different strategies, such as composites, solid solution and doping, have been developed as promising approaches to obtain zero thermal expansion materials. However, microstructure controlled zero thermal expansion behavior via interface or surface has not been realized. Here we report the observation of an impressive zero thermal expansion (volumetric thermal expansion coefficient, -1.41 × 10 K, 293-623 K) in single-crystal ferroelectric PbTiO fibers with large-scale faceted and enclosed mesopores. The zero thermal expansion behavior is attributed to a synergetic effect of positive thermal expansion near the mesopores due to the oxygen-based polarization screening and negative thermal expansion from an intrinsic ferroelectricity. Our results show that a fascinating surface construction in negative thermal expansion ferroelectric materials could be a promising strategy to realize zero thermal expansion.
几十年来，由于零热膨胀材料具有有趣的物理性质和在高精度仪器中的潜在应用，它们一直是众多研究的焦点。已经开发出不同的策略，如复合材料、固溶体和掺杂，作为获得零热膨胀材料的有前途的方法。然而，通过界面或表面控制微观结构的零热膨胀行为尚未实现。在这里，我们报告了在具有大规模面心和封闭介孔的单晶铁电 PbTiO 纤维中观察到令人印象深刻的零热膨胀（体热膨胀系数，-1.41×10-6 K-1，293-623 K）。零热膨胀行为归因于介孔附近由于基于氧的极化屏蔽的正热膨胀和来自固有铁电性的负热膨胀的协同效应。我们的结果表明，在具有负热膨胀的铁电材料中引人注目的表面构造可能是实现零热膨胀的一种有前途的策略。
