Shi Run, Wu Yonghuang, Xin Zeqin, Guo Jing, Li Zonglin, Zhao Bochen, Peng Ruixuan, Li Chenyu, Wang Enze, Wang Bolun, Zhang Xiaolong, Cheng Chun, Liu Kai
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China.
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.
Angew Chem Int Ed Engl. 2023 Apr 11;62(16):e202301421. doi: 10.1002/anie.202301421. Epub 2023 Mar 9.
The study of VO flourishes due to its rich competing phases induced by slight stoichiometry variations. However, the vague mechanism of stoichiometry manipulation makes the precise phase engineering of VO still challenging. Here, stoichiometry manipulation of single-crystal VO beams in liquid-assisted growth is systematically studied. Contrary to previous experience, oxygen-rich VO phases are abnormally synthesized under a reduced oxygen concentration, revealing the important function of liquid V O precursor: It submerges VO crystals and stabilizes their stoichiometric phase (M1) by isolating them from the reactive atmosphere, while the uncovered crystals are oxidized by the growth atmosphere. By varying the thickness of liquid V O precursor and thus the exposure time of VO to the atmosphere, various VO phases (M1, T, and M2) can be selectively stabilized. Furthermore, this liquid precursor-guided growth can be used to spatially manages multiphase structures in single VO beams, enriching their deformation modes for actuation applications.
由于轻微的化学计量比变化会诱导出丰富的竞争相，VO的研究蓬勃发展。然而，化学计量比调控的机制尚不明确，这使得VO的精确相工程仍然具有挑战性。在此，我们系统地研究了在液体辅助生长中对单晶VO梁的化学计量比调控。与先前的经验相反，在降低的氧浓度下反常地合成了富氧VO相，这揭示了液态VO前驱体的重要作用：它浸没VO晶体，并通过将它们与反应性气氛隔离来稳定其化学计量相（M1），而未被覆盖的晶体则被生长气氛氧化。通过改变液态VO前驱体的厚度，从而改变VO暴露于气氛中的时间，可以选择性地稳定各种VO相（M1、T和M2）。此外，这种液态前驱体引导的生长可用于在单个VO梁中空间管理多相结构，丰富其用于驱动应用的变形模式。
