Deposition and characterization of ternary thin films within the Ti–Al–C system by DC magnetron sputtering

Wilhelmsson, Ola; Palmquist, Jens-Petter; Lewin, Erik; Emmerlich, Jens; Eklund, Per; Persson, Per; Högberg, Hans; Li, S.; Ahuja, Rajeev; Eriksson, Olle; Hultman, Lars; Jansson, Ulf

doi:10.1016/j.jcrysgro.2006.03.008

Cited by 223 publications

(151 citation statements)

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“…The latter reaction was first reported (but not fully identified) by Wilhelmsson et al [48] and later explained by Persson et al [78,79]. The expected difference between the MAX carbonitrides and oxycarbides is that the local bonding environment for substitutional impurity atoms (N or O) in Ti 2 AlC is different from that for interstitial situations.…”

Section: Site Solid Solutionsmentioning

confidence: 86%

“…Some confusion has been caused by the fact that there is another use of the term "intergrown structure" or "intergrowth" in the MAX-phase literature, which refers to cases of irregular stacking within a MAX-phase grain (for example, the irregular stacking of a few unit cells of " Ta 2 AlC" within a Ta 4 AlC 3 grain [38], or "Ti 2 AlC" within epitaxial Ti 3 AlC 2 thin films [48] and Ti 3 AlC 2 bulk material [49]). Related observations are the reports of Ta 6 AlC 5 and Ti 7 SnC 6 stacking sequences of a few unit cells in Ta 4 AlC 3 and Ti 2 SnC samples, suggesting the possible existence of "higher-order" MAX phases (i.e., M n+1 AX n phases with n > 3) [50,51].…”

Section: Intergrown Structures -Hybrid "523" and "725" Max Phasesmentioning

confidence: 99%

“…At high temperature, epitaxial growth of a nearly phase-pure MAX phase is typically obtained, provided that the substrate is suitable. A reduction in temperature yields polycrystalline MAX-phase growth, often (depending on composition) with competing phases such 49 as Ti 5 (Si, Ge) 3 C x in the Ti-(Si,Ge)-C system [46,101] or the inverse perovskite Ti 3 AlC in the Ti-Al-C system [48]. Further reduction in temperature yields the binary carbide as the main crystalline phase, either in a nanocomposite structure together with amorphous phases [25] or in solid solution [48].…”

Section: Growth Mode As a Function Of Temperaturementioning

confidence: 99%

“…Low-temperature films differ among M-A-X systems. For example, Al tends to dissolve in TiC forming a metastable solid solution (Ti,Al)C [48], while the solubility of Si in TiC is much lower; thus, the latter system tends to yield nanocrystalline TiC together with amorphous phases (e.g., SiC) [25,101].…”

Section: Growth Mode As a Function Of Temperaturementioning

confidence: 99%

“…Thus, Ti 3 SiC 2 growth tends to yield a TiC x "incubation layer" even when no intentional seed layer is deposited. However, there are numerous examples where no incubation layer is found, e.g., Ti-Al-C [48] and V-Ge-C [99]. These observations indicate that while a seed layer can promote MAX-phase nucleation, it is not necessary as long as two conditions are fulfilled: one, that the substrate is epitaxially related to the MAX phase and two, that the A-element supersaturation is sufficient.…”

Section: Nucleation Layersmentioning

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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Section: Site Solid Solutionsmentioning

confidence: 86%