Ablation particles parameters influences on VLS oxide nanowire growing

MgO nanowires were grown using vapor-liquid-solid technique by using the Pulsed Laser Ablation method in special shadow-mask system geometry. We compared the MgO nanowires morphology below and outside the shadow-mask areas obtained by using two different laser beams (193 nm - ArF excimer, and 266 Nd:YAG fourth harmonic) for target ablation. If for the first laser beam, an MgO nanowire grows outside the mask's shadow area and the growing morphology below the mask tends to change to island growing, in the second case, the nanowire tends rather to form below the shadow-mask. Our results interpretation is based on the ablation plume particles' flux and size. In the first case, results are interpreted based on the ablated particle flux variation in the ablation plume interaction with a plane mask. In the second case, we base our interpretation on 'big' particles filtering by the ablation plume interaction with a plane mask.