Cu nanowires were electrodeposited into the nanopores of self-ordered aluminum oxide films. CuO and Cu2O nanowires were fabricated by oxidizing Cu nanowires in air. Cu nanowires oxidized at 250 degrees C transform only to Cu2O (grain size similar to 21 nm), they transform to a mixture of CuO and Cu2O above 350 degrees C and finally to CuO with a preferred orientation of CuO (I 11) at 900 degrees C. (c) 2005 American Vacuum Society.