Growth of metal oxide thin films from aqueous solution by liquid phase deposition method

The deposition process of iron oxyhydroxide (β-FeOOH) from aqueous solution system of FeOOH–NH4F·HF (aq.) with H3BO3 by the liquid phase deposition (LPD) method has been investigated. The effect of initial concentration in the treatment solution and reaction time on microstructure and orientation of the deposited films were studied by means of scanning electron microscope (SEM), X-ray diffraction (XRD) and transmission electron microscope (TEM) observation. The films deposited were constructed by small particles having a crown-like and columnar structure, depending on the concentration range in the treatment solution. XRD measurements revealed that the deposited film preferred the specific direction normal to (211) plane and the dimension of the crystallites varied with the initial concentration of the solution. The deposition process and structure of the films appeared to be strongly affected by the hydrolysis reaction of Fe3+ ions coordinated by F− and/or partial OH− ions by adding boric acid.