This study reports the synthesis of ZnAl2O4 (ZAO) nanocrystallites with various degrees of crystal quality using high-temperature annealing of efficiently cross-linked ZnO-Al2O3 core-shell nanowires. The effects of annealing temperature on the formation of ZAO nanocrystallites from ZnO-Al2O3 coreshell nanowires were investigated. X-ray diffraction patterns revealed the cubic spine] phase structure of the ZAO nanocrystallites. Scanning electron microscopy images revealed that the ZnO-Al2O3 coreshell nanowires annealed at a high temperature exhibited a rugged surface, which is associated with the formation of the ZAO phase. Transmittance electron microscopy analysis showed that the crystalline quality of each ZAO nanograin formed at 800 degrees C was inhomogeneous, and most of the ZAO phase exhibited unsatisfactory crystalline quality; however, those formed at 1000 C exhibited excellent crystalline quality. The nanowires annealed at 1000 degrees C exhibited a strong UV band emission (3.25 eV), as well as a marked visible emission band at 2.75 eV. (c) 2012 Elsevier B.V. All rights reserved.