Time-resolved visualization of the heat flow in VO₂/Al ₂O₃ films

The authors performed resistance switching of a VO2 film grown on the Al2 O3 substrate by applying electric pulses. As a consequence, Joule heat of about 1 W has been induced in a 15×50 μ m2 area between the two electrodes. Using synchrotron-based infrared microspectroscopy, the authors mapped the propagation of Joule heat around the electrodes with a micrometric spatial resolution and in a submicrosecond time scale. They found that the experimental observations are well described by the Fourier law of heat conduction demonstrating the possibility of local temperature control in a micrometric length scale.