A clean method to obtain a porous alumina template

L.A. MEIER; A.E. ALVAREZ; D.R. SALINAS; M.C. DEL BARRIO

MATERIALS LETTERS

ELSEVIER SCIENCE BV

Año: 2011 vol. 70 p. 119 - 121

0167-577X

The formation of a porous anodic alumina template using a two-step anodization process and solutions free of Cr ions was studied. Anodizing was conducted under a constant cell potential of 40 V in a 0.3 M oxalic acid electrolyte at 298 K. The chemical dissolution of the first anodizing step was carried out in a 2 M phosphoric acid solution, at 298 K. Each step of the template formation was observed by SEM (scanning electron microscopy), evaluating the structural characteristics of the corresponding surfaces. The resulting template has rounded pores (≈65 nm) that are aligned forming small domains. Although the membrane obtained does not contain fully hexagonal pores, such as those obtained using chromic acidas an attack agent between the two anodizing steps, it is equally useful for the finally purpose of producing a template forthe growth of nanowires.