Morphological Characterization of Porous Anodic Alumina Membranes Prepared in Sulphuric, Oxalic, Chromic and Phosphoric Acids

Abstract

Porous Anodic Alumina membranes (PAAM) have a significant role in nanoscale devices due to their easily tunable structural aspects and variety of applications in nanotechnology. The variable process parameters in the synthesis of PAAM were anodization potential, temperature, duration and nature of electrolyte concentration. Pores of different sizes and geometry were obtained by varying these anodization parameters. In the present work, PAAM were prepared in 0.3 M of sulphuric, oxalic, chromic and phosphoric acids as electrolyte and with anodization potentials (20, 40, 50 and 90 V) at a temperature of 8 °C. Field-emission Scanning Electron Microscopy investigations confirm the pore formation in PAAM layers. Pore ordering was calculated using the Fast Fourier transform (FFT) of top view SEM micrographs. Pore arrangement analysis of PAAM was studied using Image-J and WSxM software. Morphological features of PAAM such as pore diameter, interpore distance, porosity and pore density were calculated in all electrolytes. Results show that, PAAM formed in oxalic acid having high regularity ratio and circularity compared with other cases.