Metal-Insulator Transition of VO2: Potential in Transistors and Actuators
报告人:
刘锴博士
UCBerkeley
报告时间:
2013-04-10 15:00
报告地点:
纳米中心四楼报告厅
主办单位:
物理系
简介:
Vanadium dioxide (VO2) undergoes a metal-insulator phase transition (MIT) accompanied by a structural transition of lattice. Whether the MIT is fundamentally driven by Mott transition (electron–electron correlation) or Peierls transition (electron–lattice interaction) has been debated for decades. A threshold free electron density exists in the transition from the insulator to metal phase, implying that the MIT can be triggered by electrostatic carrier accumulation. VO2 also shrinks by a transformation strain of ~ 1% along the c axis of the metal phase (cR) across the MIT, and meanwhile outputs a huge mechanical work density.
In this talk, I will present our work on controlling and utilizing both of the electronic phase transition and the structural phase transition of VO2. A reversible control of the conductance of VO2 is realized by electrostatic gating with an electrolyte or ionic liquid as medium. And VO2-based bimorphs are fabricated as powerful linear and torsional actuators which demonstrate superior performance, high durability, diversity in responsive stimuli, and versatile working environments. These efforts make VO2 a promising material in transistors and micro actuators.
