Characterizing the Hexagonality of Anodic Aluminium Oxide Nanoporous Arrays

TL;DR

This paper introduces a method to objectively quantify the regularity and hexagonality of nanoporous anodic alumina oxide templates, which influence the properties of nanomaterials derived from them.

Contribution

It presents a novel image analysis approach combining adaptive thresholding and wave propagation to measure hexagonality, validated by comparing commercial and lab-made samples.

Findings

Lab-made templates exhibit higher hexagonality than commercial ones.

The proposed method effectively quantifies pore regularity.

Hexagonality measurement is invariant to translation, rotation, and scaling.

Abstract

Nanoporous anodized alumina oxide have been used as templates for obtaining nanomaterials such as nanowires, which exhibit interesting electronic, magnetic and optical properties. This article presents how the regularity of the spatial distribution of pores in such templates, which affects several of the physical properties of the obtained nanomaterials, has been objectively quantified. The method uses adaptive thresholding, wave propagation image analysis methods, as well as an hexagonality measurement which was found to be particularly suitable because of its locality and invariance to translation, rotation and scaling. A comparison between commercial and laboratory-made samples is presented in order to test the method, resulting higher hexagonality for the latter type of templates.