Topotaxial growth of Ti2AlN by solid state reaction in AlN∕Ti(0001) multilayer thin films

Höglund, Carina; Beckers, Markus; Schell, Norbert; Borany, J. von; Birch, Jens; Hultman, Lars

doi:10.1063/1.2731520

Cited by 40 publications

(25 citation statements)

References 11 publications

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“…References [36,38] note the deposition temperature for rocksalt (Ti, Mg)N alloys to be between 200 and 300°C with oxidization resistance close to 700°C (suitable for mid-temperature thermoelectric applications). If the layered NaCrS 2 superstructure is preferred, it would be advisable to use either high-temperature direct growth or low-temperature deposition, followed by high-temperature annealing [68] (in ammonia or nitrogen). In this case, GaN or SiC [69] substrates could be considered for their suitable lattice constant and thermal stability.…”

Section: Discussionmentioning

confidence: 99%

Theoretical study of phase stability, crystal and electronic structure of MeMgN2 (Me = Ti, Zr, Hf) compounds

et al. 2017

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Scandium nitride has recently gained interest as a prospective compound for thermoelectric applications due to its high Seebeck coefficient. However, ScN also has a relatively high thermal conductivity, which limits its thermoelectric efficiency and figure of merit (zT). These properties motivate a search for other semiconductor materials that share the electronic structure features of ScN, but which have a lower thermal conductivity. Thus, the focus of our study is to predict the existence and stability of such materials among inherently layered equivalent ternaries that incorporate heavier atoms for enhanced phonon scattering and to calculate their thermoelectric properties. Using density functional theory calculations, the phase stability of TiMgN 2 , ZrMgN 2 and HfMgN 2 compounds has been calculated. From the computationally predicted phase diagrams for these materials, we conclude that all three compounds are stable in these stoichiometries. The stable compounds may have one of two competing crystal structures: a monoclinic structure (LiUN 2 prototype) or a trigonal superstructure (NaCrS 2 prototype; R 3mH). The band structure for the two competing structures for each ternary is also calculated and predicts semiconducting behavior for all three compounds in the NaCrS 2 crystal structure with an indirect band gap and semiconducting behavior for ZrMgN 2 and HfMgN 2 in the monoclinic crystal structure with a direct band gap. Seebeck coefficient and power factors are also predicted, showing that all three compounds in both the NaCrS 2 and the LiUN 2 structures have large Seebeck coefficients. The predicted stability of these compounds suggests that they can be synthesized by, e.g., physical vapor deposition.

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Section: Discussionmentioning

confidence: 99%

Theoretical study of phase stability, crystal and electronic structure of MeMgN2 (Me = Ti, Zr, Hf) compounds

et al. 2017

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“…The deposition is then followed by annealing above the deposition temperature, to initiate transformation to the MAX phase. Examples include Ti/AlN multilayers [196], where the transformation to a phase-pure Ti 2 AlN film was reported to occur as low as 500 °C, the transformation of TiN/TiAl(N) multilayers into (Ti,Al)N/Ti 2 AlN [197], and other TiN/Al-based multilayers [198]. There are also indications that a nominally amorphous Ti-Al-C film deposited below 200 °C can transform to Ti 2 AlC when annealed at high temperature [199].…”

Section: Solid-state Reactionsmentioning

confidence: 99%

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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“…It should be pointed out that this is an unexpectedly high growth rate considering the moderate power that is applied to the 50 mm cathode in this process. The growth per energy is 0.15 Å/J, which is about two orders of magnitude higher than for MSE of AlN from a solid Al target under similar conditions 11 and about one order of magnitude higher than InN. 12 This encouragingly high deposition rate of GaN by DC-MSE has not been previously reported and subject to a separate study.…”

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confidence: 83%

Electronic-grade GaN(0001)/Al2O3(0001) grown by reactive DC-magnetron sputter epitaxy using a liquid Ga target

Junaid

Hsiao

Pališaitis

et al. 2011

Applied Physics Letters

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Electronic-grade GaN (0001) epilayers have been grown directly on Al2O3 (0001) substrates by reactive DC-magnetron sputter epitaxy (MSE) from a liquid Ga sputtering target in an Ar/N2 atmosphere. The as-grown GaN epitaxial film exhibit low threading dislocation density on the order of ≤ 1010 cm-2 obtained by transmission electron microscopy and modified Williamson-Hall plot. X-ray rocking curve shows narrow fullwidth at half maximum (FWHM) of 1054 arcsec of the 0002 reflection. A sharp 4 K photoluminescence peak at 3.474 eV with a FWHM of 6.3 meV is attributed to intrinsic GaN band edge emission. The high structural and optical qualities indicate that MSEgrown GaN epilayers can be used for fabricating high-performance devices without the need of any buffer layer.On the day of the defence date the status of this article was: Manuscript.Original Publication:Muhammad Junaid, Ching-Lien Hsiao, Justinas Palisaitis, Jens Jensen, Per Persson, Lars Hultman and Jens Birch, Electronic-grade GaN(0001)/Al2O3(0001) grown by reactive DC-magnetron sputter epitaxy using a liquid Ga target, 2011, Applied Physics Letters, (98), 14, 141915.http://dx.doi.org/10.1063/1.3576912Copyright: American Institute of Physicshttp://www.aip.org

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Topotaxial growth of Ti2AlN by solid state reaction in AlN∕Ti(0001) multilayer thin films

Cited by 40 publications

References 11 publications

Theoretical study of phase stability, crystal and electronic structure of MeMgN2 (Me = Ti, Zr, Hf) compounds

Theoretical study of phase stability, crystal and electronic structure of MeMgN2 (Me = Ti, Zr, Hf) compounds

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

Electronic-grade GaN(0001)/Al2O3(0001) grown by reactive DC-magnetron sputter epitaxy using a liquid Ga target

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