A vitreous layer of boron oxide was formed on Mg ribbons by infrared (IR) irradiation of B + B2O3 powders (10:1 in molar ratio). The surface layer exhibits an evolution from the honeycomb pattern to self-assembled array of boron oxide nanowires depending on the irradiation time. The boron oxide nanowires, approximate 40-100 nm in diameter and 1-2 mum in length, are of amorphous nature. The nanowires are likely to be grown in a self-assembled feature during the cooling process of molten B2O3 and oxidized boron. (C) 2003 Elsevier Science B.V. All rights reserved.