Das kubische Tantalmononitrid (B 1-Typ) und seine Mischbarkeit mit den isotypen Übergangsmetallnitriden und-carbiden

Gatterer, J.; Dufek, G.; Ettmayer, Peter; Kieffer, R.

doi:10.1007/bf00906226

Cited by 102 publications

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“…[7] The lattice parameter (a ϭ 4.337 Å ) for this CaF 2 -type with a body-centered tetragonal superstructure TaN x 5.77 5.01 [12] nitride obtained by Gatterer et al [6] from the elements at 2000°C and a pressure of 40 bar, and that obtained by Mashimo et al [7] (a ϭ 4.336 Å ), are almost identical. Finally, the θ-phase crystallizes hexagonal in the Bh WCtype structure type with a simple hexagonal stacking of the metal layers.…”

Section: Introductionmentioning

confidence: 79%

“…[7] The lattice parameter (a ϭ 4.337 Å ) for this [1] TaN 0.04 3.315 [2] β-phase α-phase with a cubic 3 ϫ 3 ϫ 3 superstructure TaN 0.05 10.11 (3ϫ 3.369) [1] γ-phase (β-Ta 2 N) hexagonal close-packing of the tantalum atoms TaN 0.41 3.041 4.907 [1] TaN 0.5 3.042 4.905 [2] TaN 0.5 4.928 [3] an anti-Li 2 ZrF 6 -type superstructure with aЈ ϭ Ί3a 5.283 (Ί3 ϫ 3.050) TaN 0. 43 4.919 [4] 5 [3] hexagonal, distorted B35 CoSn-type TaN 1.00 5.196 2.911 [5] δ-phase face-centered cubic, B1 NaCl-type TaN 0.92 4.337 [6] TaN 0.97 4.336 [7] θ-phase hexagonal, Bh WC-type TaN [3] TaN x cubic, CaF 2 -type TaN x 5.02 [11] CaF 2 -type with a body-centered tetragonal superstructure TaN x 5.77 5.01 [12] nitride obtained by Gatterer et al [6] from the elements at 2000°C and a pressure of 40 bar, and that obtained by Mashimo et al [7] (a ϭ 4.336 Å ), are almost identical. Finally, the θ-phase crystallizes hexagonal in the Bh WCtype structure type with a simple hexagonal stacking of the metal layers.…”

Section: Introductionmentioning

confidence: 99%

“…Upon heating in argon or ammonia, Ta 3 N 5 decomposes yielding the nitrides Ta 4 N 5 and Ta 5 N 6 . [21] The tetragonal Ta 4 N 5 [3] phase is isostructural to Nb 4 N 5 , [22] a defect variant of the NaCl-type structure.…”

Section: Introductionmentioning

confidence: 99%

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Plasma‐Enhanced CVD Synthesis and Structural Characterization of Ta₂N₃

2004

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Keywords: Tantalum / Nitrides / Plasma-enhanced chemical vapor deposition / X-ray diffraction / Electron microscopy Microcrystalline tantalum nitride films were prepared on various substrates from TaCl 5 precursor and nitrogen gas using the plasma-enhanced chemical vapor deposition (PECVD) method. Syntheses carried out at 600−650°C led to single-phase samples of the tantalum nitride Ta 2 N 3 with a defect fluorite-type structure. The anion vacancies were found to order resulting in a 2 ϫ 2 ϫ 2 cubic superstructure of the C-Ln 2 O 3 type (space group Ia3 , Z = 16) with a = 9.8205(4) Å according to a Rietveld refinement of the X-ray IntroductionThe binary TaϪN system is quite rich in compounds with well-defined and variable stoichiometries. The formal oxidation state of tantalum covers the whole range from nearly zero to the maximum of ϩ5. These compounds can be divided into four groups: solid solutions of nitrogen in tantalum, the phase with the approximate stoichiometry Ta 2 N, three phases with a nearly 1:1 composition, and nitrogenrich nitrides. A few comprehensive reviews of tantalum nitride structural chemistry are available.[1Ϫ3] Results of the previous structural studies in this binary system are summarized in Table 1.Up to 5 at.% of nitrogen can be dissolved in the bodycentered cubic lattice of elemental tantalum, for example by heating of Ta powder in ammonia at 600Ϫ700°C.[3] The lattice constant of such solid solutions increases slightly to 3.315Ϫ3.369 Å compared to that of the pure metal (a ϭ 3.311 Å ). Observation of additional weak reflections suggests a cubic superstructure with the unit cell tripled in all directions and with a β ϭ 3a α ϭ 10.11 Å . The γ-phase with the composition range TaN 0.41Ϫ0.5 , also denoted as β-Ta 2 N, [4] crystallizes with a hexagonal unit cell.[1Ϫ4] Its crystal structure can be described as a hexagonal close packing of the tantalum atoms with the nitrogen atoms filling half of the octahedral interstices. While the earlier studies suggested a statistical distribution, [1,2] electron- [3] and neutron-diffraction [4] investigations revealed a trigonal P31m supercell with aЈ ϭ Ί3a, isostructural to β-Nb 2 N [14] and of the anti-Li 2 ZrF 6 -type.[15] The γ-phase can be obtained by nitriding of tantalum powder in gaseous ammonia at 800Ϫ900°C or from the elements at 2000°C. [1,3] The hexagonal ε-phase was proposed by Schoenberg [1] to have a B35 CoSn-type structure with the composition TaN 1.00 ; the same description was given by Brauer and Zapp.[2] In this structure type the nitrogen atoms are at the center of slightly distorted tantalum octahedra. Later, Christensen and Lebech [5] showed that the nitrogen atoms are displaced from these ideal positions reducing their coordination sphere to a square pyramid. The unit cell determined by Christensen and Lebech [5] (a ϭ 5.196 Å , c ϭ 2.911 Å ) is quite similar to that given by the other authors.[1Ϫ3] The ε-phase can be obtained as a product of nitriding of Ta powder at temperatures at Ͼ 1100°C. [1] Another modification of tantalum ...

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Section: Introductionmentioning

confidence: 79%

Section: Introductionmentioning

confidence: 99%

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Plasma‐Enhanced CVD Synthesis and Structural Characterization of Ta₂N₃

2004

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“…Optical pyrometry was used to monitor the reaction temperature. The resulting black powder was found to be TaN (10) by X-ray diffraction. Na S and Rb S were made from the respective alkali metal (Na,Cerac,99.95%;Rb,Cerac,99.8%) and sulfur (Cominco American, high purity) in appropriate amounts.…”

Section: Synthesismentioning

confidence: 99%

Synthesis and Crystal Structure of Ternary SulfidesA3MS4withA=Na, Rb andM=Nb, Ta

Niewa

Vajenine

DiSalvo

1998

Journal of Solid State Chemistry

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“…21 Cubic TaN is normally made at more than 1900 K and 16 MPa of nitrogen pressure. 22 When carrying out a SSM reaction between TaCl 5 and Li 3 N ͓Eq. ͑1͔͒ under ambient conditions, the product observed is the subnitride, Ta 2 N, rather than nitrogen rich TaN…”

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confidence: 99%

Solid-state metathesis reactions under pressure: A rapid route to crystalline gallium nitride

Wallace¹,

Kim²,

Rose³

et al. 1998

Applied Physics Letters

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High pressure chemistry has traditionally involved applying pressure and increasing temperature until conditions become thermodynamically favorable for phase transitions or reactions to occur. Here, high pressure alone is used as a starting point for carrying out rapid, self-propagating metathesis reactions. By initiating chemical reactions under pressure, crystalline phases, such as gallium nitride, can be synthesized which are inaccessible when initiated from ambient conditions. The single-phase gallium nitride made by metathesis reactions under pressure displays significant photoluminescence intensity in the blue/ultraviolet region. The absence of size or surface-state effects in the photoluminescence spectra show that the crystallites are of micron dimensions. The narrow lines of the x-ray diffraction patterns and scanning electron microscopy confirm this conclusion. Brightly luminescent thin films can be readily grown using pulsed laser deposition.

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Das kubische Tantalmononitrid (B 1-Typ) und seine Mischbarkeit mit den isotypen Übergangsmetallnitriden und-carbiden

Cited by 102 publications

References 2 publications

Plasma‐Enhanced CVD Synthesis and Structural Characterization of Ta₂N₃

Plasma‐Enhanced CVD Synthesis and Structural Characterization of Ta₂N₃

Synthesis and Crystal Structure of Ternary SulfidesA3MS4withA=Na, Rb andM=Nb, Ta

Solid-state metathesis reactions under pressure: A rapid route to crystalline gallium nitride

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Das kubische Tantalmononitrid (B 1-Typ) und seine Mischbarkeit mit den isotypen Übergangsmetallnitriden und-carbiden

Cited by 102 publications

References 2 publications

Plasma‐Enhanced CVD Synthesis and Structural Characterization of Ta2N3

Plasma‐Enhanced CVD Synthesis and Structural Characterization of Ta2N3

Synthesis and Crystal Structure of Ternary SulfidesA3MS4withA=Na, Rb andM=Nb, Ta

Solid-state metathesis reactions under pressure: A rapid route to crystalline gallium nitride

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Plasma‐Enhanced CVD Synthesis and Structural Characterization of Ta₂N₃

Plasma‐Enhanced CVD Synthesis and Structural Characterization of Ta₂N₃