Synthesis and characterization of MoB2-x thin films grown by nonreactive DC magnetron sputtering
2016 (English)In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 34, 031511-1-031511-8 p.Article in journal (Refereed) Published
DC magnetron sputtering was used to depositmolybdenumboridethin films for potential low-friction applications. The films exhibit a nanocomposite structure with ∼10 nm large MoB2−x (x > 0.4) grains surrounded by a boron-rich tissue phase. The preferred formation of the metastable and substoichiometric hP3-MoB2structure (AlB2-type) is explained with kinetic constraints to form the thermodynamically stable hR18-MoB2 phase with a very complex crystal structure. Nanoindentation revealed a relatively high hardness of (29 ± 2) GPa, which is higher than bulk samples. The high hardness can be explained by a hardening effect associated with the nanocomposite microstructure where the surrounding tissue phase restricts dislocation movement. A tribological study confirmed a significant formation of a tribofilm consisting of molybdenum oxide and boron oxide, however, without any lubricating effects at room temperature.
Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2016. Vol. 34, 031511-1-031511-8 p.
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-128108DOI: 10.1116/1.4948234ISI: 000379792200027OAI: oai:DiVA.org:liu-128108DiVA: diva2:928976
Funding agencies: Swedish Research Council [621-2012-4359, 622-2008-405]; Knut and Alice Wallenbergs Foundation; Swedish Foundation for Strategic Research, SSF (FunCase) [RMA11-0029]2016-05-172016-05-172016-08-06