Bai Yihua, Gan Ke, Li Xiaohu, Duan Dongping
School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
CAS Key Laboratory of Green Process and Engineering, National Engineering Research Center of Green Recycling for Strategic Metal Resources, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
Materials (Basel). 2024 Aug 29;17(17):4275. doi: 10.3390/ma17174275.
A vanadium ion valence state constant high-entropy perovskite system was synthesized using the hydrothermal method with a trivalent vanadium ion as the vanadium source. The B-site of the perovskite crystal lattice was loaded with five atoms in equal proportions. We tried to synthesize the Sr(TiZrHfVNb)O high-entropy system using different methods. However, the valence state of the vanadium ion could only be kept constant using the hydrothermal process in the valence balanced high-entropy composition system. There was significant vanadium element segregation and second phase in the Sr(TiZrHfVNb)O system prepared using the solid-state reaction process. Also, obvious vanadium ion valence state ascending from V to V appeared in this high-entropy system with an increase in calcination temperature. Inconspicuous vanadium element segregation appeared at 900 °C, the significant segregation phenomenon and second phase appeared at 1200 °C, and the particle size increased with the temperature. This meant that the high-entropy value could not only stabilize the crystal phase, but also stabilize the ionic valence state. Moreover, the constant trivalent vanadium ion valence state could provide coordinated performance with a wide optical response range and a low band gap for the high-entropy system. This suggests that the system might grow a potential ceramic material for optical applications.
采用水热法，以三价钒离子为钒源，合成了一种钒离子价态恒定的高熵钙钛矿体系。钙钛矿晶格的B位以等比例负载了五种原子。我们尝试用不同方法合成Sr(TiZrHfVNb)O高熵体系。然而，在价态平衡的高熵组成体系中，只有采用水热法才能使钒离子的价态保持恒定。采用固态反应法制备的Sr(TiZrHfVNb)O体系中存在明显的钒元素偏析和第二相。此外，在该高熵体系中，随着煅烧温度的升高，钒离子价态出现明显从V到V的上升。在900℃时出现不明显的钒元素偏析，1200℃时出现明显的偏析现象和第二相，且粒径随温度升高而增大。这意味着高熵值不仅可以稳定晶相，还可以稳定离子价态。此外，恒定的三价钒离子价态可为高熵体系提供宽光学响应范围和低带隙的协同性能。这表明该体系可能成为一种有潜力的光学应用陶瓷材料。
