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Strontium doped lanthanum manganite thin films were deposited by pulsed laser deposition on yttria stabilized zirconia single crystals for a comprehensive electrochemical characterization of the material acting as a cathode. A physically meaningful electrical model was employed to fit the electrochemical impedance spectroscopy results in order to extract the main oxygen mass transport parameters as a function of the temperature and oxygen partial pressure. The oxygen diffusion and surface exchange coefficients extracted from the analysis showed several orders of magnitude of enhancement with respect to the bulk values reported in the literature and an unexpectedly low dependence with the oxygen partial pressure. Different observations were combined to propose a mechanism for the enhanced incorporation of oxygen in interface dominated thin films mainly based on the high concentration of oxygen vacancies expected in the grain boundaries.

The unique physical and optical properties of nanoparticles make their reliable and rapid assembly an important goal for nanotechnology. To this end, many competing driving forces have been targeted to control the self-assembly, though issues with reliability and efficiency indicate that interfaces on the nanoscale are not yet fully understood. In this letter we report for the first time that the flow of water media from the interface between chemically nanopatterned hydrophobic surfaces and adjacent hydrophilic regions (a Janus interface) can effectively be employed for rapid nanoparticle assembly with single nanoparticle resolution. We find that the dewetting of water molecules from this Janus interface drives the assembly of nanoparticles from electrostatically stabilised nanoparticle colloids onto the hydrophobic areas, expedited by removing the resistance to adhesion between wetted interfaces exerted by any hydration barrier, such that nanoparticle assembly is achieved in under a minute. We call this method of controlled nanoparticle assembly Janus Interface Nanoparticle Assembly - JINA. We then demonstrate control of this mechanism through pH switching and prove its effectiveness for fabrication by rapidly creating single-nanoparticle sites and single particle wide lines whilst simultaneously densely coating macro-scale features. Not only does this assembly method have far-reaching implications in nanomanufacturing, the unanticipated nature of this mechanism also challenges many commonly held assumptions about the interfacial interactions of nanoparticle self-assembly., Comment: 19 pages, 5 figures