Influence of deposition parameters on mechanical properties of sputter-deposited Cr₂O₃ thin films

Abstract

Among the oxides, Cr 2 O 3 exhibits the highest hardness value and a low coefficient of friction. These properties make chromium oxide an excellent coating material for tribological applications. Cr 2 O 3 thin films were deposited by radio-frequency reactive magnetron sputtering at substrate temperature in the range 363-593 K. The hardness and elastic modulus of the films were measured by two complementary nanoindentation techniques to investigate the influences of the substrate temperature and the oxygen content in the sputtering gas. While the continuous stiffness data method provides information throughout the whole film thickness, nanoindentation combined with scanning force microscopy of the residual imprints allows visualization of pileup, cracking, and delamination from the substrate. Hardness values up to 32 GPa were obtained for substrate temperatures exceeding 500 K and oxygen contents between 15% and 25% of the total gas pressure. The films, obtained with these deposition conditions, showed good adhesion to silicon substrates.

Growth and characterization of chromium oxide coatings prepared by pulsed-direct current reactive unbalanced magnetron sputtering

“…The stoichiometry of the film can significantly affect the composition of the coatings and hence the mechanical properties [37]. The maximum elastic modulus is 208 GPa for the oxygen flow rate of 9 sccm, consistent with the values from the literature [2]. At higher oxygen flow rates both the hardness and elastic modulus decreased significantly.…”

Synthesis and characterize of trivalent chromium Cr(OH) 3 and Cr 2 O 3 microspheres

“…How to control nanoparticles' size and shape, low cost and high yields is one of the aims on nanoscience research. The trivalent chromium nanoparticles in the literature could not be produced on large scale, whatever the method of electrodeposition, [11] magnetron sputtering, [12] UHV thermal oxidation, [13] MOCVD, [14] microwave heating [9] and laser irradiation be [15]. Considering Cr(III) ion possibly forming nanospheres under basic condition [16], and base on successful experiment of nanosphere fabrication [17], the Cr(VI) ion is deoxidized to Cr(III) ion and obtains trivalent chromium microspheres in our lab.…”

Thin Film and Plasma Characterization of PVD Oxides

“…This hardness level is also seen for sputter-deposited phase-pure, dense stoichiometric α-Cr2O3 [52], [48]. α-Cr2O3 has not been used in its pure form as metal cutting tool material, but is extensively used for its good corrosion protection in, e.g., high alloyed steels.…”

“…The hardness and crystallographic stability could potentially be introduced by the naturally hard and stable α-Cr2O3 [52]. The Cr-Zr-O was first deposited over the whole compositional range with reactive RF-magnetron sputtering by Spitz et al [49].…”