Properties of nanocrystalline Al-Cu-O films reactively sputtered by DC pulse dual magnetron

J. Blažek, J. Musil, P. Stupka, R. Čerstvý, J. Houška

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The article reports on the effect of the addition of copper in the Al 2 O 3 film on its mechanical and optical properties. The Al-Cu-O films were reactively co-sputtered using DC pulse dual magnetron in a mixture of Ar + O 2 . One magnetron was equipped with a pure Al target and the second magnetron with a composed Al/Cu target. The amount of Al and Cu in the Al-Cu-O film was controlled by the length of pulse at the Al/Cu target. The Al-Cu-O films with ≤16 at.% Cu were investigated in detail. The addition of Cu in Al 2 O 3 film strongly influences its structure and mechanical properties. It is shown that (1) the structure of Al-Cu-O film gradually varies with increasing Cu content from γ-Al 2 O 3 at 0 at.% Cu through (Al 8-2x ,Cu 3x )O 12 nanocrystalline solid solution to CuAl 2 O 4 spinel structure, (2) the Al-Cu-O films with ≥3 at.% Cu exhibit (i) relatively high hardness H increasing from ∼15 GPa to ∼20 GPa, (ii) enhanced elastic recovery W e increasing from ∼67% to ∼76% with increasing Cu content from ∼5 to ∼16 at.% Cu and (iii) low values of Young's modulus E* satisfying the ratio H/E* > 0.1 at ≥5 at.% Cu, and (3) highly elastic Al-Cu-O films with H/E* > 0.1 exhibit enhanced resistance to cracking during indentation under high load.

Original languageEnglish
Pages (from-to)1762-1767
Number of pages6
JournalApplied Surface Science
Issue number5
Publication statusPublished - 15 Dec 2011



  • Cu addition
  • Elasticity
  • Mechanical properties
  • Pulse reactive sputtering
  • Resistance to cracking

ASJC Scopus subject areas

  • Surfaces, Coatings and Films

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