α-Ni(OH) 2 thin films have been synthesized on various substrates by liquid phase deposition method. The deposited films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscope (SEM). The addition of boric acid (H 3 BO 3 ) as fluoride scavenger to the treatment solution destabilized the [NiF x (x-2n)-] metal-fluoro complex bonds and forced the oxide precipitation, resulting in the formation of α-Ni(OH) 2 . The obtained thin films exhibited transparency and interference color. SEM images showed that the films consisted of interconnected thread-like fibers with a width of ca. 50 nm. The deposition process and morphology of fibrous particles showed strong dependence to the initial concentrations of H 3 BO 3 solution and temperature. Transparency and interference color were related to the film thickness, which can be controlled by the concentration of Ni metal-fluoro complex and the reaction time. Calcination at 500 o C led to the formation of NiO particles. For comparison purpose, β-Ni(OH) 2 thin films prepared by "direct deposition" method which consists of simple heterogeneous nucleation in an aqueous solution without adding boric acid is reported.

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The electrical conductivity and melting behavior of alkali molten carbonates, Li2CO3 and K2CO3, coexisting with oxide particles, γ­LiAlO2 and MgO, have been investigated. The conductivity was measured by the ac impedance method. The melting of carbonates caused an abrupt change in the electrical conductivity at the transition point, Tnormalt. The value of Tnormalt decreased with decreasing melt content in the heterophase system. The activation energy, normalΔEnormala, increased with a decrease of apparent average thickness of the liquid layer. Differential thermal analysis measurements of γ­LiAlO2/Li2CO3 coexisting systems showed a shift toward lower temperatures for the endothermic peak of fusion of Li2CO3. The molar enthalpy of fusion, normalΔHnormalm, of the coexisting phase decreased with decreasing apparent average thickness. A correlation between the transition point, Tnormalt, of the electrical conductivity and the melting point of the thermal analysis, Tnormalm, was found for inorganic normalpowder/Li2CO3 coexisting systems. These variations in the properties of carbonates are attributed to the effect of the solid phase. The influence of γ­LiAlO2 powder on both transport and thermal properties of molten carbonates is greater than that of MgO particles. © 2004 The Electrochemical Society. All rights reserved.