Nanoindentation of nanocolumnar TiO2 thin films with single and stacked zig-zag layers

• Published in: Thin solid films Vol. 550; pp. 444 - 449
• Main Authors: Jiménez-Piqué, E., González-García, L., Rico, V.J., González-Elipe, A.R.
• Format: Journal Article Publication
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.2014; Elsevier
• Subjects: Angles (geometry); Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Enginyeria dels materials; Exact sciences and technology; Glancing angle deposition; Hardness; Materials science; Mechanical and acoustical properties; Mechanical properties; Methods of deposition of films and coatings; film growth and epitaxy; Modulus of elasticity; Nanoindentation; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Nanotechnology; Nanotecnologia; Other topics in nanoscale materials and structures; Pel·lícules fines; Physical properties of thin films, nonelectronic; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin films; Titanium dioxide; Vapor phase epitaxy; growth from vapor phase; Young's modulus; Àrees temàtiques de la UPC; Thin films; Young's modulus; Hardness; Titanium dioxide; Nanoindentation; Glancing angle deposition; Nanohardness; Cross section; Nanocolumn; Mechanical properties; Nanostructures; Ion beams; Young modulus; Vapor deposition; Fractures; Hardness testing; Titanium; Hardness indentation; Delamination; Cross sections
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.10.022

This paper reports a systematic analysis of the mechanical properties of nanocolumnar TiO2 thin films prepared by evaporation at a glancing geometry. A systematic study of the mechanical properties is carried out by comparing the hardness and the Young's modulus determined by nanoindentation for thin films prepared at different deposition angles and characterized by a tilted nanocolumnar structure and others where the nanocolumns are perpendicular to the substrate or are arranged as zig-zag stacked layers. A correlation between mechanical properties and glazing angle geometry is proposed. Differences in the results are discussed in view of the cross section images obtained by focused ion beam and of the deformed areas. Zig-zagged layers present lower values of hardness and Young's modulus due to the collapse of the angles of the columns, but at the same time this configuration impedes the appearance of fracture or delamination, as observed for tilted columns. •TiO2 thin films with tilted columns and zigzag microstructures were deposited.•Nanoindentation was performed on the different films.•Deformation mechanisms were identified with focused ion beam cross sections.•Mechanical response was rationalized in terms of depositing parameters.