Electrochemical preparation of crystallized Ba1-xSrxMoO4 solid-solution films at room-temperature

Crystalline solid-solution oxide films of Ba1-xSrxMoO4 have been prepared by anodization of molybdenum metal substrates in hydroxide electrolytic solutions containing Ba2+ and Sr2+ ions at room temperature (22 similar to 23 degreesC). Due to the differences in the solubilities and in the crystallization habits of BaMoO4 and SrMoO4, only Ba-enriched solid-solution films could be formed. The morphologies of the solid-solution films were similar to that of BaMoO4. The compositions of these films could be easily controlled by changing the Ba and Sr concentrations in the starting solutions. A thin layer of carbonates of Ba and/or Sr is easily formed on the outer surface due to the reaction between the residual solution on the film and ambient CO2 after the films were removed from the electrolytic solutions. This thin layer could be easily cleaned by Ar ion erosion. (C) 2001 Elsevier Science B.V. All rights reserved.