Microstructural, nanomechanical, and microtribological properties of Pb thin films prepared by pulsed laser deposition and thermal evaporation techniques
2016 (English)In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 34, no 2, 021505- p.Article in journal (Refereed) PublishedText
In this work, the authors compare the morphological, structural, nanomechanical, and microtribological properties of Pb films deposited by thermal evaporation (TE) and pulsed laser deposition (PLD) techniques onto Si (111) substrates. Films were investigated by scanning electron microscopy, surface probe microscopy, and x-ray diffraction in theta-2 theta geometry to determine their morphology, root-mean-square (RMS) roughness, and microstructure, respectively. TE films showed a percolated morphology with densely packed fibrous grains while PLD films had a granular morphology with a columnar and tightly packed structure in accordance with the zone growth model of Thornton. Moreover, PLD films presented a more polycrystalline structure with respect to TE films, with RMS roughness of 14 and 10 nm, respectively. Hardness and elastic modulus vary from 2.1 to 0.8 GPa and from 14 to 10 GPa for PLD and TE films, respectively. A reciprocal friction test has shown that PLD films have lower friction coefficient and wear rate than TE films. Our study has demonstrated for first time that, at the microscale, Pb films do not show the same simple lubricious properties measured at the macroscale. (C) 2015 American Vacuum Society.
Place, publisher, year, edition, pages
A V S AMER INST PHYSICS , 2016. Vol. 34, no 2, 021505- p.
IdentifiersURN: urn:nbn:se:liu:diva-127283DOI: 10.1116/1.4936080ISI: 000372352300027OAI: oai:DiVA.org:liu-127283DiVA: diva2:921561
Funding Agencies|Italian National Institute of Nuclear Physics (INFN); Italian Ministry of Research of FIRB [RBFR12NK5K]; Swedish Government Strategic Research Area Grant in Materials Science (SFO Mat-LiU) on Advanced Functional Materials2016-04-202016-04-192016-04-20