Hexagonal VO2 particles: synthesis, mechanism and thermochromic properties
Hui Yan Xu1,2, Ke Wei Xu1,3, Fei Ma1,2
1State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University Xi'an 710049 Shaanxi China mafei@mail.xjtu.edu.cn.
Abstract:
Monoclinic vanadium dioxide VO2 (M) with hexagonal structure is synthesized by hydrothermal method, and the phase evolution is evidenced. Interestingly, the hexagonal morphology comes into being as a result of the low-energy coherent interfaces, (211̄)1//(21̄1̄)2 and (21̄1̄)1//(020)2. The size of hexagonal particles is well controlled by changing the concentration of precursor solutions. Hexagonal particles exhibit excellent thermochromic properties with a narrow hysteresis of 5.9 °C and high stability. In addition, the phase transition temperature can be substantially reduced down to 28 °C by simply W doping.
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