Synthesis and growth mechanism of Cr-doped ZnO single-crystalline nanowires

Cr-doped ZnO single-crystalline nanowires are fabricated by a facile wet-chemical route. The nanowires show stable room-temperature ferromagnetic behavior. Calculations indicate that most of the magnetic moment is induced by Cr 3d and O 2p exchange interactions. The initial adsorption of dopants on the specific nanocrystal surface and the following oriented attachment of preformed nanocrystals play key roles in the doping process.