Solubility of nitrogen in liquid nickel and binary Ni–Xi alloys (Xi=Cr, Mo,W, Mn, Fe, Co) under elevated pressure

Kowanda, C.; Speidel, Markus O.

doi:10.1016/s1359-6462(02)00628-0

Cited by 96 publications

(63 citation statements)

References 15 publications

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“…At low pressures, the solubility of N into metal melts may be described by Sievert's law (e.g., Kowanda & Speidel, ). Following the reaction

½ N_{2 ((), gas)} \Leftrightarrow N_{metal}

the equilibrium constant K for this reaction is

normalK = \frac{a_{N}}{\sqrt{{p_{N}}_{2}}} = \frac{f_{N} \times ([], % N)}{\sqrt{{p_{N}}_{2}}}

using the terms of the steel industry where a N is the activity of nitrogen; f N is the activity coefficient in the liquid alloy; [% N] is the amount of dissolved nitrogen in the alloy, given in wt%; and p N2 is the partial pressure of N in the gas phase (in bar).…”

Section: Discussionmentioning

confidence: 99%

Nitrogen Solubility in Core Materials

Speelmanns

Schmidt

Liebske

2018

Geophysical Research Letters

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During accretion, nitrogen was distributed between metal melt, silicate melt, and the atmosphere and today's N deficit of bulk silicate Earth with respect to chondrites may be due to segregation into the core and/or atmospheric losses. To examine the former, we experimentally determined N solubilities in Fe-dominated metal melts at 1200-1800°C, 0.4-9.0 GPa. Results show that pressure has a strong positive influence on N solubility, increasing from 1.0 to 7.4 wt% at 1-9 GPa (1400°C) while temperature has the inverse effect, N solubility decreasing from 1.3 to 0.6 wt% at 1200-1800°C (1 GPa). The solubility data are parameterized as function of pressure and temperature. Our results suggest that core-forming metal melts can dissolve large quantities of N, and the potential N contribution to the Earth's core density deficit could hence be much larger than previously assumed. Most importantly, N in the deep reduced mantle should be stored in the small metal fractions and not in silicates.Plain Language Summary On the early Earth nitrogen was redistributed between three prevailing reservoirs: the core forming metal, the silicate magma ocean, and the atmosphere. To shed light on the behavior of N during core segregation, we have experimentally determined N solubilities in Fe-dominated metal melts at high temperatures and pressures (1200-1800°C, 0.4-9.0 GPa) using high-pressure devices. Based on our experimental results a model has been developed to describe N solubility into metal melts as a function of pressure and temperature. The model suggests that core-forming metal melts can dissolve N quantities that are as high as the Earth's core density deficit. However, the N concentrations in the core-forming metal are dependent on the accretionary scenario and its partitioning with silicate magma ocean; our solubilities provide an upper limit for possible N concentrations within the Earth's core. Nevertheless, this study shows that N in the modern mantle will largely dissolve in its small metal fraction and not in the dominating silicates.

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“…At low pressures, the solubility of N into metal melts may be described by Sievert's law (e.g., Kowanda & Speidel, ). Following the reaction

½ N_{2 ((), gas)} \Leftrightarrow N_{metal}

the equilibrium constant K for this reaction is

normalK = \frac{a_{N}}{\sqrt{{p_{N}}_{2}}} = \frac{f_{N} \times ([], % N)}{\sqrt{{p_{N}}_{2}}}

Section: Discussionmentioning

confidence: 99%

Nitrogen Solubility in Core Materials

Speelmanns

Schmidt

Liebske

2018

Geophysical Research Letters

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“…The binary Ni-B and Ni-N phase diagrams show that approximately 30 weight % (wt%) B is in a liquid phase at 1550°C (23), whereas the solubility of N in liquid Ni is only 0.0012 wt% at 1550°C at 1 atm of N 2 (24). Thus the yield of recrystallized hBN is controlled by the N solubility in the liquid phase of the Ni solvent.…”

mentioning

confidence: 99%

“…Thus the yield of recrystallized hBN is controlled by the N solubility in the liquid phase of the Ni solvent. Kowanda and Speidel reported that the N solubility of a liquid Ni-Mo alloy increases with an increasing concentration of Mo; the addition of Mo of 40 wt% to the Ni solvent enhances the solubility of N by 40 times as compared to that in the pure Ni (24). We thus added Mo to the Ni solvent so as to increase N content in solution.…”

mentioning

confidence: 99%

Deep Ultraviolet Light-Emitting Hexagonal Boron Nitride Synthesized at Atmospheric Pressure

Kubota

Watanabe

Tsuda

et al. 2007

Science

1,119

653

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estimates the population relaxation rate. However, this remains under investigation.The AT splitting and gain without inversion in the Mollow absorption spectrum imply that the absorption and gain inside a single QD are tunable. In the AT configuration, the absorption of the probe beam can be switched on and off by applying a strong optical field. In contrast, in the MAS experiment, the absorption of the frequency fixed probe beam can be tuned to be positive or negative (gain) by adjusting the pump field strength. Our results are the first step toward the realization of electromagnetically induced transparency and lasing without inversion in the spinbased lambda system and suggest that QDs offer the potential to be used as elements in optoelectronics and quantum logic devices (4, 27).Note added in proof: Since the submission of this paper, two papers have appeared on http://arxiv.org that report studies of the resonant excitation of quantum dots in the strong excitation regime. The first (31) reports a measurement of the fluorescence correlation function that Mollow first calculated, and the second (32) reports Rabi oscillations.References and Notes 1. D. Loss, D. P. DiVincenzo, Phys. Rev. A. 57, 120 (1998 Materials emitting light in the deep ultraviolet region around 200 nanometers are essential in a widerange of applications, such as information storage technology, environmental protection, and medical treatment. Hexagonal boron nitride (hBN), which was recently found to be a promising deep ultraviolet light emitter, has traditionally been synthesized under high pressure and at high temperature. We successfully synthesized high-purity hBN crystals at atmospheric pressure by using a nickelmolybdenum solvent. The obtained hBN crystals emitted intense 215-nanometer luminescence at room temperature. This study demonstrates an easier way to grow high-quality hBN crystals, through their liquid-phase deposition on a substrate at atmospheric pressure.H exagonal boron nitride (hBN) and cubic boron nitride (cBN) are known as the representative crystal structures of BN. hBN is chemically and thermally stable and has been widely used as an electrical insulator and heat-resistant material for several decades; cBN, which is a high-density phase, is almost as hard as diamond (1).Promising semiconductor characteristics due to a direct band gap of 5.97 eV were recently discovered in high-purity hBN crystals obtained by a high-pressure flux method, paving the way for a material that efficiently emits deep ultraviolet (DUV) light (2, 3). Similar to aluminum nitride (AlN) (4) and gallium nitride (GaN) (5), hBN may have attractive potential as a wide-band gap material. The layered structure of hBN makes the material mechanically weak, but it has greater chemical and thermal stability than GaN and AlN. The interesting optical properties of hBN, such as its huge exciton-binding energy (2), are due to its anisotropic structure, whereas a single crystal's basal plane in hBN is not easily broken because of its strong in-plane bonds. T...

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“…2. 35,36 On the other hand, the nitridation of Cr appears beneficial to the corrosion prevention similarly as mentioned with Fig. 4 when we compare the chemical corrosion rates of electroplated Cr and nitrided Cr of the same thickness.…”

Section: Corrosion Behaviors Of Crn Layermentioning

confidence: 53%

Corrosion Prevention of Chromium Nitride Coating with an Application to Bipolar Plate Materials

et al. 2014

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The corrosion properties of chromium nitride (CrN) coating on nickel have been evaluated in order to improve the anti-corrosion of metallic bipolar plate materials with applications such as redox flow batteries. The CrN layers are prepared by nitridation of electroplated Cr layers with different thickness. The nitrogen content of CrN coating layers varies from 0.5 to 4.2 wt% depending on nitriding time and coating layer thickness. Electrochemical and chemical corrosion behaviors are investigated by potentiodynamic polarization test in 5% sulfuric acid and by immersion test in 50% sulfuric acid, respectively. Electrochemical analysis of corrosion potential and corrosion current density as well as passivation behavior and chemical corrosion rate prove conclusively that an intact thin CrN layer is more corrosion resistant than thicker layers where cracks are developed. Sheet resistance of CrN coating layers before and after the corrosion test exhibits no significant difference. The improved corrosion resistance and the excellent stability of CrN coating layers suggest an efficient anti-corrosion method for metallic bipolar plate materials.

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Solubility of nitrogen in liquid nickel and binary Ni–Xi alloys (Xi=Cr, Mo,W, Mn, Fe, Co) under elevated pressure

Cited by 96 publications

References 15 publications

Nitrogen Solubility in Core Materials

Nitrogen Solubility in Core Materials

Deep Ultraviolet Light-Emitting Hexagonal Boron Nitride Synthesized at Atmospheric Pressure

Corrosion Prevention of Chromium Nitride Coating with an Application to Bipolar Plate Materials

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