Ordered arrays of self-assembled ErSi2-x, SMSi2-x, and DySi2-x nanowires aligned along Si [1 1 0] have been grown at 600degreesC on Si(0 0 1) vicinal substrates. The nanowires grow perpendicular to the Si dimer rows and are 1.5-5 nm wide, approximately 2 monolayers high and up to 1 mum long. These nanowires were characterized in situ with scanning tunneling microscopy. (C) 2002 Elsevier Science B.V. All rights reserved.