ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
Epitaxial Mn+1AXn phase (n=1, 2 or 3) thin films from the chemically related Ti-Si-C, Ti-Ge-C, andTi-Sn-C systems were grown on Al2O3(0001) substrates at temperatures in the region of 700-1000oC, using d.c. magnetron sputtering from individual sources. In addition to growth of the knownphases Ti3SiC2, Ti3GeC2, Ti2GeC, and Ti2SnC the method allows synthesis of the new phasesTi4SiC3, Ti4GeC3, and Ti3SnC2 as well as the intergrown structures Ti5A2C3 and Ti7A2C5 in the Siand Ge systems. Characterization by XRD, TEM and nanoindentation show similarities with respectto phase distribution, mechanical, and electrical properties, particularly pronounced whencomparing Si and Ge. The Ti-Sn-C system is, however, the most liable system with respect tosurface segregation of the A-element. This causes less favorable growth of MAX phases as seen bya preferential growth of the binary carbide TiC and metallic Sn. Nanoindentation on films from theTi-Si-C and Ti-Ge-C systems shows large plastic deformation with extensive pile up. The typicalthin film hardness is [removed info]20 GPa, and the Young’s modulus in the region of 320 GPa. The four-pointprobe resistivity is low for all systems, but differs depending on materials system and phase, withvalues of [removed info]25 μ[removed info]cm for Ti3SiC2, and [removed info]17 μ[removed info]cm for Ti2GeC
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.45.2648.pdf
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