二氧化钒外延薄膜的相变调控及多场耦合性能研究

Vanadium dioxide thin film has wide applications due to that its metal-insulator phase transition temperature is around room temperature and the resistance of the film has a dramatic change near the transition temperature. In order to further expand the application scope, investigating the phase transition mechanism and tuning the transition properties are very important. This project will focus on preparing high quality epitaxial vanadium dioxide thin films on different substrates using a simple and economic method, polymer-assisted deposition, to tune the stress of the films. Then the films can be doped by ions with large magnetic moment by this method, which can form ordered structure under magnetic field and enhance the coupling between magnetic field and vanadium dioxide thin films. By fully studying the transition characteristics of stressed and doped vanadium dioxide thin films under different fields, it is helpful to control the transition utilizing extra coupling fields and understand the mechanism of phase transition, which can promote the applications of vanadium dioxide film based functional devices.

由于二氧化钒薄膜的金属-绝缘体相变温度在室温附近，相变时电阻变化极大，因此具有广阔的应用前景，而研究二氧化钒的相变机理以及调控其相变性能对于实现二氧化钒薄膜的应用就尤为重要。本项目主要通过一种经济的薄膜制备方法——高分子辅助沉积法在不同基底上制备高质量的外延二氧化钒薄膜调制薄膜应力，并通过该方法掺杂具有较大电子磁矩的离子，以此增强磁场与二氧化钒薄膜的耦合效应。薄膜应力以及掺杂离子在磁场下形成有序结构都可以调控二氧化钒中的电子态从而调制其相变温度以及性能。通过系统研究磁场、热场、应力场等多场耦合下薄膜的相变特性，寻找多场耦合下二氧化钒相变的有效调控方法，进一步理解二氧化钒的相变机制，为拓展二氧化钒功能器件的应用奠定材料基础。

二氧化钒薄膜的金属绝缘体相变性能在二氧化钒薄膜的应用中起着非常重要的作用。本项目基于高分子辅助沉积方法，实现了较高质量的二氧化钒薄膜的制备。在此基础上，一方面，通过不同取向基底、斜切基片、柔性基底、薄膜厚度、离子掺杂等调控薄膜应力，实现了对二氧化钒薄膜相变性能的调制。另一方面，制备了以二氧化钒薄膜为功能材料的柔性传感器件原型，并研究了其在人体生理信号监测方面的应用。这些研究结果对于拓展二氧化钒薄膜的应用具有较好的指导意义。