Thermal stability of Ti3SiC2 thin films

Emmerlich, Jens; Mušić, Denis; Eklund, Per; Wilhelmsson, Ola; Jansson, Ulf; Schneider, Jochen M.; Högberg, Hans; Hultman, Lars

doi:10.1016/j.actamat.2006.10.010

Cited by 216 publications

(156 citation statements)

References 20 publications

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“…This is supported by studies on decomposition of MAX-phases (cf., section 7). For example, during post-annealing, Si starts to evaporate from Ti 3 SiC 2 thin films in vacuum at 1000-1160 o C [245,246], which is consistent with studies on bulk Ti 3 SiC 2 in vacuum [247]. On the other hand, if the A element has a high vapor pressure, decomposition to MX can occur at much lower temperature, as demonstrated for Ti 2 InC [248] and Ti 2 AlN [147].…”

Section: Temperature Ranges For Max-phase Synthesissupporting

confidence: 66%

“…More important, however, is again the fact that the decomposition temperature depends strongly on the environment and on impurities. Annealing of epitaxial Ti 3 SiC 2 thin films in vacuum [245,246] showed the onset of Ti 3 SiC 2 decomposition in the range 1000-1100 °C rather than 1800 °C as reported for bulk [314,315]. With the presence of an interface to ambient, the chemical potentials for the elements are reduced, while in the presence of oxygen, surface oxides form diffusion barriers against further decomposition.…”

Section: Decomposition Mechanism Of Max Phase Thin Filmsmentioning

confidence: 90%

“…Several reports [245,246] have indicated that there is an apparent difference between epitaxial thinfilm samples and bulk samples with respect to the decomposition of MAX phases. This is partly a consequence of the fact that the diffusion length scales and the sensitivity of the analysis methods are different.…”

Section: Decomposition Mechanism Of Max Phase Thin Filmsmentioning

confidence: 99%

“…With the presence of an interface to ambient, the chemical potentials for the elements are reduced, while in the presence of oxygen, surface oxides form diffusion barriers against further decomposition. Initial annealing experiments by Emmerlich [245] with two Ti 3 SiC 2 (0001) films mechanically placed face-to-face showed that the Ti 3 SiC 2 films were stable to at least 1400 °C. The observed increase in decomposition temperature compared with the vacuum-annealed samples can be attributed to the absence of an interface to vacuum, and to the entrapment of Si by the surface oxide.…”

Section: Decomposition Mechanism Of Max Phase Thin Filmsmentioning

confidence: 99%

“…Emmerlich et al [245] developed a model for the decomposition of Ti 3 SiC 2 epitaxial thin films in vacuum; this model is relevant to any MAX-phase vacuum annealing experiment. Figure 19 is a schematic illustration of the mechanism of Ti 3 SiC 2 decomposition [245].…”

Section: Decomposition Mechanism Of Max Phase Thin Filmsmentioning

confidence: 99%

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The M+1AX phases: Materials science and thin-film processing

et al. 2010

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This article is a critical review of the M n+1 AX n phases ("MAX phases", where n =1, 2, or 3) from a materials science perspective. MAX phases are a class of hexagonal-structure ternary carbides and nitrides ("X") of a transition metal ("M") and an A-group element. The most well known are Ti 2 AlC, Ti 3 SiC 2 , and Ti 4 AlN 3 . There are ~60 MAX phases with at least 9 discovered in the last five years alone. What makes the MAX phases fascinating and potentially useful is their remarkable combination of chemical, physical, electrical, and mechanical properties, which in many ways combine the characteristics of metals and ceramics. For example, MAX phases are typically resistant to oxidation and corrosion, elastically stiff, but at the same time they exhibit high thermal and electrical conductivities and are machinable. These properties stem from an inherently nanolaminated crystal structure, with M n+1 X n slabs intercalated with pure A-element layers. The research on MAX phases has been accelerated by the introduction of thin-film processing methods.Magnetron sputtering and arc deposition have been employed to synthesize single-crystal material by epitaxial growth, which enables studies of fundamental materials properties. However, the surface-initiated decomposition of M n+1 AX n thin films into MX compounds at temperatures of 1000-1100 °C is much lower than the decomposition temperatures typically reported for the corresponding bulk material. We also review the prospects for low-temperature synthesis, which is essential for deposition of MAX phases onto technologically important substrates. While deposition of MAX phases from the archetypical Ti-Si-C and Ti-Al-N systems typically require synthesis temperatures of ~800 °C, recent results have demonstrated that V 2 GeC and Cr 2 AlC can be deposited at ~450 °C. Also, thermal spray of Ti 2 AlC powder has been used to produce thick coatings. We further treat progress in the use of first-principles calculations for predicting hypothetical MAX phases and their properties. Together with advances in processing and materials 3 analysis, this progress has led to recent discoveries of numerous new MAX phases such as Ti 4 SiC 3 , Ta 4 AlC 3 , and Ti 3 SnC 2 . Finally, important future research directions are discussed. These include charting the unknown regions in phase diagrams to discover new equilibrium and metastable phases, as well as research challenges in understanding their physical properties, such as the effects of anisotropy, impurities, and vacancies on the electrical properties, and unexplored properties such as superconductivity, magnetism, and optics. 4

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