Phase transitions in vanadium oxide nanostructures

二氧化钒，VO2，当它被加热到68 ℃的临界温度Tc以上时，经历从绝缘相到金属态的转变。这种转变背后的确切机制仍然存在争议，主要是因为局部应变和Tc之间的耦合使得推断真实的在西雅图的华盛顿大学的大卫科布登教授开创了一种研究这个问题的新方法，通过使用VO2“纳米束”，小于特征域尺寸。然而，迄今为止，所有的结果都是使用光学显微镜和电测量悬浮在触点之间的纳米梁获得的。在沃里克，在电子显微镜的专业知识，提供了一个机会，以前所未有的细节研究绝缘和金属相之间的域边界，以回答长期存在的问题和从教授Cobden的工作产生的新问题的目的。2011年夏季将实施一项短期研究计划，这笔旅费赠款将为制定未来研究提案提供机会，使我们能够维持这种新的合作。

Vanadium dioxide, VO2, undergoes a transition from an insulating phase to a metallic state when it is heated above a critical temperature Tc of 68C. The precise mechanisms underlying this transformation remain controversial, primarly because coupling between local strain and Tc makes it very challenging to infer the true (microscopic) properties of the material from macroscopic measurements that average over a large volume.A new way to study this problem has been pioneered by Prof. David Cobden at the University of Washington in Seattle, by using VO2 'nanobeams', smaller than the characteristic domain size. However all the results to date have been obtained using optical microscopy and electrical measurements of nanobeams suspended between contacts. The expertise at Warwick, in electron microscopy, provides an opportunity to study the domain boundary between the insulating and metallic phases in unprecedented detail, with the aim of answering long-standing problems and new questions arising from Prof. Cobden's work. A short programme of research is in place for the summer of 2011, and this travel grant will provide an opportunity to develop proposals for future research, enabling us to sustain this new collaboration.