Influence of strain on latent heat of VO2 ceramics
Influence of strain on latent heat of VO2 ceramics
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DOI：
10.1016/j.jallcom.2018.04.094
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发表时间：
2018-06-30
影响因子：
6.2
通讯作者：
Kinemuchi, Yoshiaki
中科院分区：
文献类型：
--
作者：
Kato, Kunihiko;Lee, Jeongbin;Kinemuchi, Yoshiaki
二氧化钒（VO 2）在67摄氏度下经历金属-绝缘体转变（MIT），是一种有吸引力的热应用材料，具有与冰水相当的潜热。在这里，我们已经调查了潜热的变化，由于残余应变引起的放电等离子烧结（SPS）。SPS压力线性地增加了不均匀应变的程度，从而减少了潜热并拓宽了MIT温度范围。MIT的光学观察揭示了在高度应变的样品中的缓慢转变。高应变VO 2的适度退火可以消除这种应变，从而恢复高潜热。本研究表明，在VO 2陶瓷的本征潜热的利用应变调谐的重要性。(C)2018 Elsevier B. V.版权所有。
Vanadium dioxide (VO2), which undergoes a metal-insulator transition (MIT) at 67 degrees C, is an attractive material for caloric applications, possessing a latent heat comparable to that of ice-water. Here, we have investigated the variation in latent heat due to residual strain induced by spark plasma sintering (SPS). SPS pressure linearly increased the degree of inhomogeneous strain, thereby reducing the latent heat and broadening the MIT temperature range. Optical observation of MIT revealed a slow transition in highly strained samples. Moderate annealing of highly strained VO2 can eliminate this strain, and thereby recover the high latent heat. The present study indicates the importance of strain tuning for the utilization of intrinsic latent heat in VO2 ceramics. (C) 2018 Elsevier B.V. All rights reserved.