Completely Filling Anodic Aluminum Oxide with Maghemite Nanoparticles by Dip Coating and Their Magnetic Properties

Anodic aluminum oxide (AAO) nanotemplates were completely filled with maghemite (γ-Fe 2 O 3 ) nanoparticles by a dip-coating process and their magnetic properties were investigated. Maghemite particles with ―20 nm diameter and stabilized by oleic acid were selectively deposited into AAO pores with ∼100 nm diameter. The multiple layers of particles were obtained by repeating the procedures of dip coating and removing oleic acids from the particles. The magnetic moment of AAO with particles increased in proportion to the number of layers. These results demonstrate the possibility of integrating nanoparticles into nanotemplates and controlling their properties.