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- Högberg, Hans, 1968-, et al.
(författare)
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Growth and characterization of MAX-phase thin films
- 2005
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Ingår i: Surface and Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 193, s. 6-10
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Tidskriftsartikel (refereegranskat)abstract
- We report that magnetron sputtering can be applied to synthesize MAX-phase films of several systems including Ti–Si–C, Ti–Ge–C, Ti–Al–C, and Ti–Al–N. In particular, epitaxial films of the known phases Ti3SiC2, Ti3GeC2, Ti2GeC, Ti3AlC2, Ti2AlC, and Ti2AlN as well as the newly discovered thin film phases Ti4SiC3, Ti4GeC3 and intergrown structures can be deposited at 900–1000 °C on Al2O3(0001) and MgO(111) pre-seeded with TiC or Ti(Al)N. From XTEM and AFM we suggest a growth and nucleation model where MAX-phase nucleation is initiated at surface steps or facets on the seed layer and followed by lateral growth. Differences between the growth behavior of the systems with respect to phase distribution and phase stabilities are discussed. Characterization of mechanical properties for Tin+1Si–Cn films with nanoindentation show decreased hardness from about 25 to 15 GPa upon penetration of the basal planes with characteristic large plastic deformation with pile up dependent on the choice of MAX material. This is explained by cohesive delamination of the basal planes and kink band formation, in agreement with the observations made for bulk material. Measurements of the electrical resistivity for Ti–Si–C and Ti–Al–N films with four-point probe technique show values of 30 and 39 μΩ cm, respectively, comparable to bulk materials.
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| 2. |
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| 3. |
- Molina-Aldareguia, J.M., et al.
(författare)
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Kink formation around indents in laminated Ti3SiC2 thin films studied in the nanoscale
- 2003
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Ingår i: Scripta Materialia. - 1359-6462 .- 1872-8456. ; 49:2, s. 155-160
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Tidskriftsartikel (refereegranskat)abstract
- The deformation mechanisms in ductile Ti3SiC2(0 0 0 1) single-crystal films have been analysed by nanoindentation and cross-sectional transmission electron microscopy. Permanent deformation includes formation of kink bands, as the nanolaminated material buckles out at the perimeter of the contact area, and delamination cracks. Evidence is presented for incipient kink-band formation.
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| 4. |
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| 5. |
- Scabarozi, T.H., et al.
(författare)
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Weak electronic anisotropy in the layered nanolaminate Ti 2 GeC
- 2008
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Ingår i: Solid State Communications. - : Elsevier BV. - 0038-1098 .- 1879-2766. ; 146:11-12, s. 498-501
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the anisotropy in electronic transport of the layered ternary Ti2GeC by comparing the results of measurements on c-axis oriented epitaxial thin-film and polycrystalline bulk samples. The electrical conductivities, Hall coefficients, and magnetoresistances were analyzed within a multi-band framework. An adequate description of the magnetotransport data on the film with the highest mobility required the use of the explicit field-dependent conductivity tensor with three conduction bands. The analysis indicated that n ˜ p, although with n ˜ 3.5 × 1027 m- 3. The ratio of the a- to c-axis conductivities is small and contrary to theoretical predictions. © 2008 Elsevier Ltd. All rights reserved.
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