外部温度对二氧化钒临界相变电场影响的研究  

Influence of external temperature on electric field MIT of vanadium dioxide

作　　者：山世浩 王庆国 曲兆明 

机构地区：[1]陆军工程大学(石家庄校区)静电与电磁防护研究所,河北石家庄050003

出　　处：《兵器材料科学与工程》2017年第6期39-42,共4页Ordnance Material Science and Engineering

基　　金：国家自然科学基金(51277180)

摘　　要：通过无机溶胶-凝胶法和真空退火工艺在Al2O3陶瓷基片上制备出VO2薄膜,通过在薄膜上施加高电压,并结合温度控制系统的方法,研究相变过程中外部温度对二氧化钒临界相变电场的影响。结果表明:当外部温度从63.5℃增加到66℃时,相变需要的临界电场强度从0.17 MV/m下降到0.065 MV/m;随着外加电场强度由0.075 MV/m增加到0.2 MV/m时,相变临界温度从66℃降低到63.5℃,这说明VO2薄膜的相变存在温度与电场互相调控的现象;其相变行为由温度产生的电子热运动能和外场产生的电势能协同控制,但温度与电场的协同效应并非简单的叠加关系,即外界温度越低,温度对相变电场调控的效果越明显,外部电场强度越低,对相变温度的调控越明显;当外加温度为64~68℃,VO2薄膜相变需要的外部电场强度小于0.1 MV/m,满足智能电磁防护材料的要求。这为VO2薄膜应用于智能电磁防护材料提供可能性。VO2 thin films were prepared on Al2 O3 ceramic substrates by inorganic sol-gel method and vacuum annealing process.The effect of external temperature on the electric field（E）metal-insulator transition（MIT）of vanadium dioxide during phase transition was studied by applying a high voltage to the film and combining with the temperature control system. The results show that when the external temperature increases from 63.5 ℃ to 66 ℃,the MIT field strength decreases from 0.17 MV/m to 0.065 MV/m. With the external electric field increasing from 0.075 MV/m to 0.2 MV/m,the MIT temperature（TMIT）decreases from66 ℃ to 63.5 ℃. This shows that the phase transition of VO2 thin film has the relationship between temperature and electric field,and the MIT behavior is controlled by the thermal kinetic energy of the electrons produced by the temperature and the potential energy generated by the field. But the synergistic effect of temperature and electric field is not a simple superposition relationship. This means that the lower the external temperature,the more obvious the control effect of temperature on the MIT electric field;the lower the external field strength,the more obvious the control effect of field strength on the MIT temperature.When the applied temperature is between 64 ℃ and 68 ℃,the external electric field of VO2 thin film is less than 0.1 MV/m,which meets the requirements of intelligent electromagnetic protective material.

关 键 词：二氧化钒薄膜 临界相变电场 相变温度 智能电磁防护材料 

分 类 号：O484.4[理学—固体物理]