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Keywords:

  • functional coatings;
  • MAX phases;
  • PLD;
  • thin film analysis

Abstract

Pulsed laser deposition (PLD) employing a pulsed Nd:YAG laser was used to grow thin films from a pre-synthesized Cr2AlC MAX phase ablation target onto MgO(100), amorphous SiO2 and stainless steel substrates. The depositions were carried out for substrate temperatures from room temperature to 650 °C. For one set of samples, a 200 eV argon ion-beam was directed towards the substrate during deposition, while an otherwise identical control set was deposited without such an ion-beam. The composition, structure and properties of the films were investigated by glow-discharge optical emission spectroscopy (GDOES) for film thickness and composition, X-ray diffraction (XRD) for the phase analysis and electron microscopy for the microstructure of the films. Furthermore, electrical conductivity and hardness of the films was measured. Depending on the deposition temperature, either amorphous films or the formation of Cr7C3 and Cr2Al inside amorphous parts was observed. In all cases, the film composition did not represent the original stoichiometric composition of the target. Instead, a loss of especially aluminium and carbon was observed. The ion-beam has several interesting effects on film thickness and composition, concentration gradients in the films and on conductivity and hardness. So far, no clear model can be presented, which can summarize these effects.