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

Crystalline solid-solution oxide films of Ba1-xSrxMoO4 have been prepared b y anodization of molybdenum metal substrates in hydroxide electrolytic solu tions containing Ba2+ and Sr2+ ions at room temperature (22 similar to 23 d egreesC). Due to the differences in the solubilities and in the crystalliza tion habits of BaMoO4 and SrMoO4, only Ba-enriched solid-solution films cou ld 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 d ue to the reaction between the residual solution on the film and ambient CO 2 after the films were removed from the electrolytic solutions. This thin l ayer could be easily cleaned by Ar ion erosion. (C) 2001 Elsevier Science B .V. All rights reserved.