UNLABELLED We have proposed a method to probe metal to insulator transition in VO2 measuring photoluminescence response of colloidal quantum dots deposited on the VO2 film. In addition to linear luminescence intensity decrease with temperature that is well known for quantum dots, temperature ranges with enhanced photoluminescence changes have been found during phase transition in the oxide. Cor...

A comparison of the oxidation of bulk lead with the oxidation of thin lead layers on an inert gold substrate provides important information on both processes, particularly on the transition from surface to bulk oxidation. The exposure to oxygen of bulk polycrystalline lead at room temperature rapidly produces an oxide layer which grows laterally as a film 2.0 ± 0.2 monolayers thick, followed by...

In complex materials observed electronic phases and transitions between them often involve coupling between many degrees of freedom whose entanglement convolutes understanding of the instigating mechanism. Metal-insulator transitions are one such problem where coupling to the structural, orbital, charge, and magnetic order parameters frequently obscures the underlying physics. Here, we demonstr...

In any artificial photosynthetic system, the oxidation of water to molecular oxygen provides the electrons needed for the reduction of protons or carbon dioxide to a fuel. Understanding how this four-electron reaction works in detail is important for the development of improved robust catalysts made of Earth-abundant materials, like first-row transition-metal oxides. Here, using time-resolved F...

Transition metal oxides are widely used in solar cells, batteries, transistors, memories, transparent conductive electrodes, photocatalysts, gas sensors, supercapacitors, and smart windows. In many of these applications, large surface areas and pore volumes can enhance molecular adsorption, facilitate ion transfer, and increase interfacial areas; the formation of complex oxides (mixed, doped, m...

The oxides of many transition metals wet their own metal surface. The adhesion energy at this interface (E(adh,ox/m)) provides extra stabilization, which lowers the O2 pressure required for oxide stability as a thin film below that required for bulk-oxide stability by the factor exp[(2gamma(g/ox) - E(adh,ox/m))/(tN(ox)RT)], where gamma(g/ox) is the surface energy of the oxide, t is the oxide fi...

A thermodynamic model has been developed which predicts the growth of either an initial (semi-)coherent, strained crystalline oxide phase or an initial amorphous oxide phase (with a possible amorphous-to-crystalline transition) on the bare single-crystalline metal substrate as function of the metal-substrate orientation, the growth temperature and the oxide-film thickness. The model accounts fo...

important reactions occurring in automotive catalytic converters where both reactants are undesirable pollutants. Base-metal oxides, mixed metal-oxide compounds such as perovskites, supported metal catalysts, metal zeolites, and alloys have all been investigated as heterogeneous catalysts for this reaction, which does not occur directly in the gas phase at room temperature to any measurable ext...