Nanomaterials Produced by Ablation and Pulsed Laser Deposition

Abstract

Examinations on the PLD layers of FeAl and Ni 3 Al intermetallics produced using an excimer KrF are presented. The thickness of deposited layers was dependent on substrate temperature and ion energy. Nano-structure to fine-grained micro-structure in the range from 50 to 1000 nm was formed in deposited thin layer in respect to the deposition conditions. The stoichiometry transfer was under examination in the case of the ablated FeAl and Ni 3 Al targets. Diffractometric measurements have shown that at high laser fluence by ablation of the FeAl target, the matrix comprises the polycrystalline Fe 3 Al intermetallic phase, while at low fluence, the matrix comprises a solid solution of aluminium in iron (amorphous phase). Ablation of the Ni 3 Al target led to the matrix comprising the nanocrystalline Ni 5 Al 3 orthorombic and the Ni 3 Al 4 cubic phases. Titanium nitride thin layers were fabricated by PLD using a Nd:YAG laser on both metallic (ferritic steel) and polyurethane substrates by ablation of pure titanium in nitrogen environment. On-axis and off-axis geometry of deposition on metallic substrate was applied. Residual stresses were measured in the TiN phase showing the compressive values in the range of -6 to -8 GPa for the on-axis growth while of about -2.8 GPa for the off-axis position. Texture examinations revealed the {110} main texture component in the substrate while differences were stated in the TiN phase in respect to the geometry of deposition. In the case of on-axis growth, the mostly axial texture with the plane {110} parallel to surface with tendency to the {110} was observed, while in the case of the off-axis growth the very pronounced {112} dominant orientation was stated. Examinations of crystallite size and lattice strain were carried out on the basis of the diffraction line broadening. Deposition of the TiN at ambient conditions on the polyurethane substrate revealed uniform thin layers. Residual stresses showed the compressive stresses of about - 1500 MPa. The measured texture was stated to be close random. Morphology of deposited layers was examined by means of AFM revealed similarity to the 3D growth mechanism.