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Vanadium dioxide (VO2) features a pronounced, thermally-driven metal-to-insulator transition at 340 K. Employing epitaxial stress on rutile $$\text{TiO}_{2}(001)$$ TiO 2 ( 001 ) substrates, the transition can be tuned to occur close to room temperature. Striving for applications in oxide-electronic devices, the lateral homogeneity of such samples must be considered as an important prerequisite for efforts towards miniaturization. Moreover, the preparation of smooth surfaces is crucial for vertically stacked devices and, hence, the design of functional interfaces. Here, the surface morphology of $$\text{VO}_2/\text{TiO}_2(001)$$ VO 2 / TiO 2 ( 001 ) films was analyzed by low-energy electron microscopy and diffraction as well as scanning probe microscopy. The formation of large terraces could be achieved under temperature-induced annealing, but also the occurrence of facets was observed and characterized. Further, we report on quasi-periodic arrangements of crack defects which evolve due to thermal stress under cooling. While these might impair some applicational endeavours, they may also present crystallographically well-oriented nano-templates of bulk-like properties for advanced approaches.

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Metals near quantum critical points have been predicted to display universal out-of equilibrium behavior in the steady current-carrying state. We have studied the non-linear conductivity of high-quality CaRuO 3 thin films with residual resistivity ratio up to 57 using micro-second short, high-field current pulses at low temperatures. Even for the shortest pulses of 5 µs, Joule heating persists, making it impossible to observe a possible universal non-linearity. Much shorter pulses are needed for the investigation of universal non-linear conductivity. arXiv:1402.6845v1 [cond-mat.mtrl-sci]