抗坏血酸调控二氧化钒金属-绝缘体相变温度机理及其应用研究

Vanadium dioxide (VO2) has a metal-insulator transition occurring at about 340K. This phase transition has a strong switching effect.Therefore, this feature has been widely used in intelligent temperature control windows, fixed-temperature heat sensor, laser protection and other fields.The key of this technique is to control the temperature of vanadium dioxide phase transition.Previous studies on the control of phase transition temperature mainly focused on element doping. The phase transition temperature can changed by changing the doped elements and adjusting the amount of doped elements.The limitation of this method is that doping can introduce defects and reduce the switching effect.In addition, doping is difficult to perform on the finished VO2.Therefore, according to the principle of phase transition, ascorbic acid (AA) was taken as a reducing agent by chemical method for electron injection to change the phase transition temperature under the condition of weak lattice failure.The preliminary results of differential scanning calorimeter showed that the phase change peak of VO2 powder treated with AA did shift, and the phase change temperature shift was confirmed by NMR.We will explore the mechanism of phase transition temperature change and study the optimal scheme for regulating phase transition temperature based on this.The idea of AA treatment is low cost, simple process, and can directly operate on the finished VO2, which will promote the wider application of VO2. At the same time, this study will help reveal the complex phase transition mechanism of VO2.

二氧化钒（VO2）在340K左右会发生金属-绝缘体转变，性能突变，有很强的开关效应。因此这种特性在智能控温窗、定温热传感器、激光保护等领域得到了广泛的应用。而该应用技术的关键则在于对二氧化钒相变温度的调控。以往控制相变温度的研究多集中在元素掺杂，通过改变掺杂元素以及调整掺杂量来进行相变温度的改变。这种方法的局限性在于掺杂会引入缺陷，使得其开关效应降低。为此申请人依据相变原理，选用化学方法取抗坏血酸（AA）作为还原剂进行电子注入，对晶格弱破坏条件下改变相变温度。初步差示扫描量热仪的结果发现AA处理后的VO2粉体相变峰确实发生了偏移,变温核磁共振也证实了相变温度的偏移。申请人将探究相变温度改变及开关效应变化的机理，并依据此研究调控相变温度和开关效应的最优方案。AA处理这一方法成本低廉，过程简单，而且可以直接对成品VO2操作，将促进VO2更广泛应用。同时该研究将有助于VO2复杂相变机理的揭示。

二氧化钒（VO2）在340K左右会发生金属-绝缘体转变，性能突变，有很强的开关效应。因此这种特性在智能控温窗、定温热传感器、激光保护等领域得到了广泛的应用。而该应用技术的关键则在于对二氧化钒相变温度的调控。以往控制相变温度的研究多集中在元素掺杂，这种方法的局限性在于掺杂会引入缺陷，使得其开关效应降低。为此依据相变原理，选用化学方法取抗坏血酸（AA）作为还原剂进行电子注入，对晶格弱破坏条件下改变相变温度。基于以上我们通过微波水热的方法制备了纳米级的VO2样品，并在制备过程中通过调节制备条件改变样品的形貌和相变温度等特征。提出了一种新的二氧化钒高质量样品生长的方法，并且提出了一种二氧化钒形貌和相变温度调控的新方法。验证了微波水热钨掺杂样品相变温度的降低的可行性。通过不断摸索磁控溅射加退火的方法制备出成相较好的VO2薄膜。提出了一种新的二氧化钒薄膜的制备方法。通过对VO2进行抗坏血酸处理，验证了其可以对VO2相变温度进行调控。提出了一种简单高效的 VO2相变温度调控的工艺方法。通过理论计算，探究出了抗坏血酸处理后VO2的相变温度降低的机理。提出了一种新的相变理解，有助于人们加深对二氧化钒相变的理解。通过对VO2电子注入计算的延伸扩展，计算得到了8个新磁性半导体。