The Effect of Annealing on the Raman Spectra of Porous Anodic Alumina Films Formed in Different Electrolytes

Porous anodic alumina films were formed in various acidic electrolytes. The features of its Raman spectra determined by the electrolyte nature are observed. As the thermal treatment could make the different impact on the chemical structure and optical properties of porous Al2O3 formed in the different electrolytes, the porous alumina samples were annealed at different temperatures up to 500 degrees C and the effect of the annealing on the Raman spectra is analyzed. It is shown that the choice of the annealing temperature can affect significant changes in the Raman scattering of porous alumina matrix. Depending on the electrolyte, these changes could concern both intensity and the shape of the Raman spectra. PAA fabricated in the selenic acid solution demonstrate the weakest dependence of the Raman response on the annealing temperature. Thus it is good candidate for PAA application as the matrices for the formation and Raman investigation of nanocomposites when the processes of nanostructures synthesis require heat-treatment procedures.