liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
Microstructure and nonbasal-plane growth of epitaxial Ti2AlN thin films
Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics.
Show others and affiliations
2006 (English)In: Journal of Applied Physics, ISSN 0021-8979, Vol. 99, no 3Article in journal (Refereed) Published
Abstract [en]

Thin films of the Mn+1AXn (MAX) phase (M: early transition metal, A:A-group element, X: C and/or N, n=1-3) Ti2AlN were epitaxially grown onto single-crystal MgO(111) and MgO(100) substrates by dc reactive magnetron cosputtering from Ti and Al targets in an Ar/N2 gas mixture at a temperature of 690°C. To promote the nucleation of the MAX phase, a fcc (Ti0.63Al0.37)N seed layer was deposited before changing to Ti2AlN growth parameters. The nucleation processes have been studied by real-time in situ specular x-ray reflectivity. Independent of substrate orientation, the seed layer shows no roughening until its final thickness of approximately 100 Å, indicating pseudomorphic layer-by-layer growth. The MAX phase shows heteroepitaxial layer-by-layer growth on MgO(111), with increased surface roughening up to approximately 200 Å, whereas on MgO(100) the growth mode changes to Volmer-Weber-type already after three monolayers. X-ray scattering in Bragg-Brentano geometry of the final, approximately 1000 Å thick, Ti2AlN film reveals lattice parameters of c=13.463 Å and a=2.976 Å on the MgO(111) substrate and c=13.740 Å and a=2.224 Å on the MgO(100) substrate. From pole figure measurements the orientational relationship between film and substrate lattice was determined to be MgO{111}〈110〉//Ti2AlN{1012} 〈1210〉, regardless of the substrate orientation. This tilted, nonbasal-plane growth leads to a threefold grain orientation of Ti 2AlN along the MgO〈110〉 directions and a polycrystalline morphology confirmed by cross-sectional transmission electron microscopy. The growth can be assumed to take place in a lateral step-flow mode, i.e., emerging low surface free-energy (0001) planes, on which arriving atoms can diffuse until finding a step where they are bound to A facets. This growth process is irrespective of orientational relationship between substrate and film. However, in the present low-temperature case the partitioning of arriving Al and Ti atoms during nucleation is suppressed, which as a result of interfacial adaptation between substrate and film induces standing a-type planes during growth. © 2006 American Institute of Physics.

Place, publisher, year, edition, pages
2006. Vol. 99, no 3
National Category
Natural Sciences
URN: urn:nbn:se:liu:diva-30389DOI: 10.1063/1.2161943Local ID: 15937OAI: diva2:251211
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2016-08-31

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Hultman, Lars
By organisation
The Institute of TechnologyThin Film Physics
In the same journal
Journal of Applied Physics
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 35 hits
ReferencesLink to record
Permanent link

Direct link