Electrical, mechanical and other properties of ceramic materials can be controlled by designing their microstructures. It had generally been difficult to utilize a magnetic field for tailoring the microstructure in feeble magnetic ceramics, such as Al 2 O 3 ; however, the possibility of controlling the microstructure by a magnetic field occurred with the development of superconducting magnets. In this review paper, we introduce a novel processing for the microstructual design in ceramics by colloidal processing in a strong magnetic field and an electric field. We demonstrate that the textured alumina can be fabricated by slip casting in a strong magnetic field and the production of alumina/alumina laminar composites with different crystalline-oriented layers can be achieved by electrophoretic deposition in a strong magnetic field. In order to control the texture using a magnetic field, a good dispersion of powder in a suspension is necessary because a strong attractive force between the agglomerated particles prevents each particle in a suspension from rotating in the magnetic field. The degree of orientation depends on the processing factors, such as heating temperature, viscosity of suspension, etc. And the grain growth in Al 2 O 3 matrix enhances crystallographic texture development. The bending strength of the laminar composite depended on the direction of the multilayered microstructure with alternate crystalline-oriented layers. Crack propagation and fracture mode depend on the direction of microstructure in the laminar composite with controlled crystalline orientation. q

A novel method based on the application of a square‐wave pulse potential of 50% duty cycle has been demonstrated to obtain dense bubble‐free deposits of alumina by constant voltage electrophoretic deposition (EPD) from an aqueous suspension. Application of continuous dc voltage invariably resulted in the incorporation of bubbles in the deposits. Bubbles in the deposit decreased progressively with decrease in the size of pulse width during the pulse potential EPD. A unique and narrow band of pulse width exists for each voltage within which a bubble‐free deposit is obtained. The band is wider at low applied voltages than at higher voltages. Such bands of pulse width were found to be independent of substrate material and occurred at the same range for stainless steel and nickel substrates, suggesting that the process may be generic and applicable to any conductive substrate. The green density of deposits obtained by pulse EPD has been found to be the same as those obtained by continuous dc voltage EPD. The cathodic pulse EPD produced uniform and homogeneous deposits and was more convenient and amenable to better control than anodic pulse EPD.

No abstract

This work explores the potentiality of Mo 6 clusters as new inorganic sensitizers with amphoteric properties for photoelectronic applications being non-toxic and stable. It reports on the design of photoelectrodes by electrophoretic deposition (EPD) of molybdenum octahedral metal cluster iodide (CMI) onto mesoporous TiO 2 and NiO layers before being deposited on FTO (i. e. CMI@TSO@FTO, TSO = TiO 2 or NiO). Indeed, the low-cost, lowwaste and industrially scalable EPD method has allowed for the achievement of transparent,

International audienceThis study reports the first integration of inorganic tantalum octahedral metal atom clusters into multifunctional nanocomposite coating materials and devices for window technology and energy saving applications. [Ta6Br12i](n+) (n = 2, 3 or 4) cluster-based high visible transparency UV and NIR filters are realized. Green and brown colored films are fabricated by coating on an indium-doped tin oxide glass substrate by electrophoretic deposition, an industrialized solution process. The efficiency in energy saving of the new UV-NIR filters was estimated by the determination of different figure of merit (FOM) values, such as Tvis, Tsol and Tvis/Tsol (Tsol = solar transmittance and Tvis = visible transmittance), and the color coordinates (x, y, z and L*a*b). The Tvis/Tsol ratio is equal to 1.25 for the best films. Such values are evidence of a higher energy saving efficiency than most of the inorganic composites reported in the literature. These promising results pave the way for the use of transition metal clusters as a new class of nanocoatings in energy saving window-based applications

No abstract

No abstract

International audienceThe first step of the integration of molybdenum clusters as new absorbers in all inorg. solar cells inspired from perovskite cells have been investigated via the fabrication of first cluster sensitized solar cells. The latter have been realized from the photoelectrodes obtained by chemisorption of the clusters on TiO2 and NiO films (resp. named photoanodes and photocathodes). Photovoltaic characteristics reveal that photoinduced electron or hole transfers can occur from the cluster units to the n- or p-type semiconductors resp. These first photovoltaic performances highlight the interest in using this inorg. cluster as new absorber for photo-electronical systems