Abstract: Based on PAAO's unique cellular hexagon morphology and composition, various alumina fibers (nano-belts, nano-rods, and nano-tubes) were fabricated by simply employing a dilute acid etching method. Scanning electron microscope (SEM) incorporated with energy dispersive X-ray spectroscope (EDS) and transmission electron microscope (TEM) were applied to characterize these nano-fibers. It is proved that alumina nano-fibers are formed from the porous layer, while totally different behaviors of the barrier layer and the porous layer are showed during the etching process. The orientated etching, resulted from PAAO's particular morphology and composition, is believed to be the main reason that explains the formation of different alumina nano-fibers.

Key words: alumina nano-fibres, anodic alumina, porous layer, barrier layer