A method for sintering nanoparticles by applying voltage is presented. This electrical sintering method is demonstrated using silver nanoparticle structures ink-jet-printed onto temperature-sensitive photopaper. The conductivity of the printed nanoparticle layer increases by more than five orders of magnitude during the sintering process, with the final conductivity reaching 3.7 × 10(7) S m(-1) at best. Due to a strong positive feedback induced by the voltage boundary condition, the process is very rapid-the major transition occurs within 2 µs. The best obtained conductivity is two orders of magnitude better than for the equivalent structures oven-sintered at the maximum tolerable temperature of the substrate. Additional key advantages of the method include the feasibility for patterning, systematic control of the final conductivity and in situ process monitoring. The method offers a generic tool for electrical functionalization of nanoparticle structures.

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Iron oxide thin films were grown with gas-phase deposition on a glass substrate in order to study the effects of the deposition temperature and time on the film properties. Characterization of the samples was performed using x-ray photoelectron spectroscopy, x-ray diffraction, and atomic force microscopy. It was observed that the film deposited at 350• C consisted of g-Fe 2 O 3 whereas films produced at temperatures between 400• C and 500• C could be identified as a-Fe 2 O 3 . Increasing the deposition temperature resulted in an increase of the grain size at temperatures between 350• C and 450 • C. When the deposition time was decreased, a part of the iron ions were observed to be in the divalent state.

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