Direct Synthesis of a Metal/Superconducting Oxide Composite by Oxidation of a Metallic Precursor

Yurek, G. J.; Sande, J. B. Vander; Wang, W.; Rudman, D. A.

doi:10.1149/1.2100260

Cited by 29 publications

(10 citation statements)

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“…reactions are a rapid and inexpensive route to forming near-surface ceramic phase structures on or in metallic substrates. Thermal oxidation of metallic-bearing precursors has been successfully exploited for the synthesis of thick film (oxide superconductors) and bulk complex ceramics (e.g., refs and ). However, in general, it has proven difficult to directly and controllably form complex ceramic phases via gas reactions because of the differences in the availability and thermodynamic stability of the metal components in the metallic precursor alloy.…”

Section: Discussionmentioning

confidence: 99%

Synthesis of Ternary Nitrides from Intermetallic Precursors: Modes of Nitridation in Model Cr₃Pt Alloys To Form Cr₃PtN Antiperovskite and Application to Other Systems

et al. 2004

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The use of intermetallic alloy precursors is explored as a new means to synthesize complex transition and refractory metal nitrides, carbides, and related phases. The conditions under which model single-phase Cr 3 Pt and two-phase Cr 3 Pt-dispersed Cr alloys form Cr 3 PtN antiperovskite when thermally nitrided were studied. Phenomenological experiments suggest that the key variable to achieving single-phase Cr 3 PtN surface layers is the Cr 3 Pt phase composition. In two-phase β-Cr-Cr 3 Pt alloys, the formation of single-phase Cr 3 PtN at Cr 3 -Pt precipitates by in-place internal nitridation was found to be a strong function of the size of the Cr 3 Pt dispersion in the microstructure. Nanoscale Cr 3 Pt dispersions were readily converted to near single-phase Cr 3 PtN, whereas nitridation of coarse Cr 3 Pt particles resulted in a cellular or discontinuous-type reaction to form a lath mixture of Cr 3 PtN and a more Cr-rich Cr 3 Pt or β-Cr. The potential for using such external/internal oxidation phenomena as a synthesis approach to layered or composite surfaces of ternary ceramic phases (nitrides, carbides, borides, etc.) of technological interest such as the Ti 3 AlC 2 phase, bimetallic nitride, and carbide catalysts (Co 3 Mo 3 N and Co 3 Mo 3 C and related phases), and magnetic rare earth nitrides (Fe 17 Sm 2 N x or Fe 17 Nd 2 N x ) is discussed.

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Section: Discussionmentioning

confidence: 99%

Synthesis of Ternary Nitrides from Intermetallic Precursors: Modes of Nitridation in Model Cr₃Pt Alloys To Form Cr₃PtN Antiperovskite and Application to Other Systems

et al. 2004

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“…6,7 The DIMOX™ process relies on the oxidation of molten aluminum in air at ϳ1200°C. The microstructure consists of columnar grains of ␣-Al 2 O 3 that are separated by aluminum.…”

Section: Introductionmentioning

confidence: 99%

“…Reaction-based processes for metal oxides include the directed metal oxidation (DIMOX™) process, which was developed by Lanxide in 1986, 5 and the solid metallic precursor (SMP) method. 6,7 The DIMOX™ process relies on the oxidation of molten aluminum in air at ϳ1200°C. The microstructure consists of columnar grains of ␣-Al 2 O 3 that are separated by aluminum.…”

Section: Introductionmentioning

confidence: 99%

The Reaction‐Bonded Aluminum Oxide (RBAO) Process: II, The Solid‐State Oxidation of RBAO Compacts

Suvacı

Simkovich

Messing

2000

Journal of the American Ceramic Society

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The oxidation kinetics and the fraction of aluminum that is oxidized via solid-gas reaction in reaction-bonded aluminum oxide (RBAO) compacts are shown to be strongly dependent on the oxidation temperature and the characteristics (size and green density) of the RBAO compact. Based on the Biot number, the oxidation process of RBAO compacts is controlled by convective heat transfer. Low heat transfer from the surface of the compact results in too-rapid oxidation, thermal gradients, and core-shell oxidation of the compacts. Uniform oxidation of RBAO compacts is possible by oxidizing at low temperatures (400°-470°C), where slow surface reaction of the aluminum particles controls the oxidation of the compact. A grain model is presented to cover both linear and nonlinear oxidation regimes during the oxidation of a RBAO compact, and this model predicts the experimental results when surface reaction of the aluminum particles is the rate-controlling mechanism and oxidation of the compact occurs uniformly.

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“…58 Hydrothermal syntheses have yielded celsian or hydrated aluminosilicates (e.g., cymrite, BaAl 2 Si 2 O 8 ⅐H 2 O) at even lower temperatures. [59][60][61] A relatively new method for producing shaped, alkalineearth-bearing ceramics (e.g., cerate, 62 cuprate, [63][64][65] ferrite, 66 titanate, 67,68 and aluminosilicate 19,[69][70][71] compounds) is to oxidize shaped, solid, alkaline-earth-metal-bearing precursors. Precursors containing alkaline-earth metals (barium, strontium, calcium, and magnesium) can be sufficiently malleable as to be formed by rolling, extrusion, or pressing without the use of organic binders.…”

Section: Introductionmentioning

confidence: 99%

“…Precursors containing alkaline-earth metals (barium, strontium, calcium, and magnesium) can be sufficiently malleable as to be formed by rolling, extrusion, or pressing without the use of organic binders. 19,[62][63][64][65][66][67][68][69] Alkaline-earth metals undergo rapid oxidation at modest temperatures (Յ550°C), [72][73][74][75] so that bulk precursors containing such metals can be oxidized in reasonable times. 19,62,67 Perhaps the most unique feature of this process is the use of counteracting, reaction-induced volume changes to produce near-net-shaped ceramics.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Celsian (BaAl₂Si₂O₈) from Solid Ba‐Al‐Al₂O₃‐SiO₂ Precursors: I, XRD and SEM/EDX Analyses of Phase Evolution

Allameh

Sandhage

1997

Journal of the American Ceramic Society

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An intimate Ba-Al-Al 2 O 3 -SiO 2 powder mixture, produced by high-energy milling, was pressed to 3 mm thick cylinders (10 mm diameter) and hexagonal plates (6 mm edgeto-edge width). Heat treatments conducted from 300°to 1650°C in pure oxygen or air were used to transform these solid-metal/oxide precursors into BaAl 2 Si 2 O 8 . Barium oxidation was completed, and a binary silicate compound, J ournal 3109 Prior work has revealed that novel reaction paths to Ba-CeO 3 , 62 BaFe 12 O 19 , 66 BaTiO 3 , 67,68 and YBa 2 Cu 3 O y 64 can be accessed by the oxidation of solid, alkaline-earth-metal-bearing precursors. The purpose of the present paper is to identify the reaction path(s) to celsian from a Ba-Al-Al 2 O 3 -SiO 2 precursor. Knowledge of the reaction path to celsian is considered an important first step in the processing of celsian-based composites. Before discussing the results of such work, prior analyses of phase evolution to celsian from mixed salt and metallic precursors is reviewed. II. Reaction Paths to Celsian (1) Mixed Salt PrecursorsSeveral authors have examined the formation of celsian from powder mixtures containing BaCO 3 and kaolin. [39][40][41][42][43]49 Heating such precursors at 6°-10°C/min in the temperature range ∼400°-665°C results in appreciable weight loss because of the dehydroxylation of kaolinite. 40,42,49 Weight-loss measurements also have indicated the onset of BaCO 3 decomposition above ∼600°C. 40,42,49 Further annealing in the temperature range 650°-800°C has yielded an amorphous oxide. 2,[41][42][43]49 Hexacelsian had been reported to form during annealing at Ն825°C, whereas the onset of monoclinic celsian formation has required further heat treatment at ∼1130°-1200°C. 2,39,[41][42][43]49 Based on infrared spectroscopy and X-ray diffraction (XRD) analyses, Planz and Muller-Hesse 39 have reported that the loss of H 2 O from kaolin leads to the formation of the metakaolin structure described by Brindley and Nakahira, 81 in which a layer of corner-sharing and edge-sharing AlO 4 tetrahedra is joined to a layer of SiO 4 tetrahedra. This metakaolin precursor is believed to yield an ordered form of hexacelsian with a layer of cornersharing AlO 4 tetrahedra joined to a layer of SiO 4 tetrahedra (as opposed to a ␤-hexacelsian structure with aluminum and silicon distributed in a more random fashion within a double layer of corner-sharing tetrahedra 33 ).

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Direct Synthesis of a Metal/Superconducting Oxide Composite by Oxidation of a Metallic Precursor

Abstract: not Available.

Cited by 29 publications

References 0 publications

Synthesis of Ternary Nitrides from Intermetallic Precursors: Modes of Nitridation in Model Cr₃Pt Alloys To Form Cr₃PtN Antiperovskite and Application to Other Systems

Synthesis of Ternary Nitrides from Intermetallic Precursors: Modes of Nitridation in Model Cr₃Pt Alloys To Form Cr₃PtN Antiperovskite and Application to Other Systems

The Reaction‐Bonded Aluminum Oxide (RBAO) Process: II, The Solid‐State Oxidation of RBAO Compacts

Synthesis of Celsian (BaAl₂Si₂O₈) from Solid Ba‐Al‐Al₂O₃‐SiO₂ Precursors: I, XRD and SEM/EDX Analyses of Phase Evolution

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Direct Synthesis of a Metal/Superconducting Oxide Composite by Oxidation of a Metallic Precursor

Abstract: not Available.

Cited by 29 publications

References 0 publications

Synthesis of Ternary Nitrides from Intermetallic Precursors: Modes of Nitridation in Model Cr3Pt Alloys To Form Cr3PtN Antiperovskite and Application to Other Systems

Synthesis of Ternary Nitrides from Intermetallic Precursors: Modes of Nitridation in Model Cr3Pt Alloys To Form Cr3PtN Antiperovskite and Application to Other Systems

The Reaction‐Bonded Aluminum Oxide (RBAO) Process: II, The Solid‐State Oxidation of RBAO Compacts

Synthesis of Celsian (BaAl2Si2O8) from Solid Ba‐Al‐Al2O3‐SiO2 Precursors: I, XRD and SEM/EDX Analyses of Phase Evolution

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Synthesis of Ternary Nitrides from Intermetallic Precursors: Modes of Nitridation in Model Cr₃Pt Alloys To Form Cr₃PtN Antiperovskite and Application to Other Systems

Synthesis of Ternary Nitrides from Intermetallic Precursors: Modes of Nitridation in Model Cr₃Pt Alloys To Form Cr₃PtN Antiperovskite and Application to Other Systems

Synthesis of Celsian (BaAl₂Si₂O₈) from Solid Ba‐Al‐Al₂O₃‐SiO₂ Precursors: I, XRD and SEM/EDX Analyses of Phase Evolution