Effect of the ruthenium incorporation on iron oxide phases synthesis, Fe2O3 and Fe3O4, at low annealing temperature

The aim of this work is to make easier the elaboration of two iron oxide phases, Hematite (Fe2O3) and magnetite (Fe3O4) at the same annealing temperature, by alloying with ruthenium and to widen the scope of sprayed-iron oxide thin films. Two procedures were followed for Ru-alloyed iron oxide thin films elaboration: the first one consists of spraying FeCl3 center dot 6H(2)O(0.03 M)-based aqueous solution onto glass substrates heated at 350 degrees C, on which was sprayed, immediately, an aqueous RuCl3 center dot 3H(2)O solution, during shorter time, at the same spray conditions with different molar ratios as RuCl3 center dot 3H(2)O: FeCl3 center dot 6H(2)O = x:1-x, wherein 0 <= x < 0.50. The second procedure consists of preparing an aqueous solution of ferric chloride (FeCl3 center dot 6H(2)O) and ruthenium (III) chloride hydrate (RuCl3 center dot 3H(2)O)) with other different molar ratios as RuCl3 center dot 3H(2)O: FeCl3 center dot 6H(2)O = x':1-x', wherein 0 <= x' < 0.50. This solution is sprayed onto glass substrates heated at 350 degrees C. Afterward, the as obtained films are annealed under vacuum at the fixed conditions: Pressure congruent to 10(-4) Pa, duration = 5h, temperature = 350 degrees C. XRD, and SEM analyses as well as optical, and electrical measurements, showed the effect of ruthenium incorporation into iron oxide films. Fe3O4 was obtained as well as Fe2O3 at this low annealing temperature depending on the ruthenium amount. Optical properties of the Ru-alloyed iron oxide films had really improved. Furthermore the electrical behavior showed a variation versus the ruthenium concentrations.