Grain Growth Studies of Silicon Nitride Dispersed in an Oxynitride Glass

Krämer, Martin; Hoffmann, Michael J.; Petzow, G.

doi:10.1111/j.1151-2916.1993.tb04015.x

Cited by 122 publications

(66 citation statements)

References 13 publications

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“…The rates are highly anisotropic, with preferred growth parallel to the c-axis, yielding long grains with strongly faceted prism faces. 212 …”

Section: (7) Equilibrium Intergranular and Surficial Filmsmentioning

confidence: 99%

“…The lanthanide glass samples used either yttrium-aluminum-(YAl-) or lanthanum-aluminum-(LaAl-) doped silicon oxynitride (SiON) glass. 212 The calcium-doped SiON glass-Si 3 N 4 samples were made by Tanaka. 180,213 The oxygen content was 1.3 wt% and the calcium concentration was 450 ppm, with no other cation impurities detected.…”

Section: (B) In Situ Dispersion Force Determination By Sr-veelsmentioning

confidence: 99%

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Origins and Applications of London Dispersion Forces and Hamaker Constants in Ceramics

French

2000

Journal of the American Ceramic Society

263

100

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The London dispersion forces, along with the Debye and Keesom forces, constitute the long-range van der Waals forces. London's and Hamaker's work on the point-to-point dispersion interaction and Lifshitz's development of the continuum theory of dispersion are the foundations of our understanding of dispersion forces. Dispersion forces are present for all materials and are intrinsically related to the optical properties and the underlying interband electronic structures of materials. The force law scaling constant of the dispersion force, known as the Hamaker constant, can be determined from spectral or parametric optical properties of materials, combined with knowledge of the configuration of the materials. With recent access to new experimental and ab initio tools for determination of optical properties of materials, dispersion force research has new opportunities for detailed studies. Opportunities include development of improved index approximations and parametric representations of the optical properties for estimation of Hamaker constants. Expanded databases of London dispersion spectra of materials will permit accurate estimation of both nonretarded and retarded dispersion forces in complex configurations. Development of solutions for generalized multilayer configurations of materials are needed for the treatment of more-complex problems, such as graded interfaces. Dispersion forces can play a critical role in materials applications. Typically, they are a component with other forces in a force balance, and it is this balance that dictates the resulting behavior. The ubiquitous nature of the London dispersion forces makes them a factor in a wide spectrum of problems; they have been in evidence since the pioneering work of Young and Laplace on wetting, contact angles, and surface energies. Additional applications include the interparticle forces that can be measured by direct techniques, such as atomic force microscopy. London dispersion forces are important in both adhesion and in sintering, where the detailed shape at the crack tip and at the sintering neck can be controlled by the dispersion forces. Dispersion forces have an important role in the properties of numerous ceramics that contain intergranular films, and here the opportunity exists for the development of an integrated understanding of intergranular films that encompasses dispersion forces, segregation, multilayer adsorption, and structure. The intrinsic length scale at which there is a transition from the continuum perspective (dispersion forces) to the atomistic perspective (encompassing interatomic bonds) is critical in many materials problems, and the relationship of dispersion forces and intergranular films may represent an important opportunity to probe this topic. Am. Ceram. Soc., 83 [9] 2117-46 (2000 Centennial FeatureThe London dispersion force is retarded at large separations, where the transit time of the electromagnetic interaction must be considered explicitly. Novel phenomena, such as equilibrium surficial films and bimodal wettin...

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“…The rates are highly anisotropic, with preferred growth parallel to the c-axis, yielding long grains with strongly faceted prism faces. 212 …”

Section: (7) Equilibrium Intergranular and Surficial Filmsmentioning

confidence: 99%

Section: (B) In Situ Dispersion Force Determination By Sr-veelsmentioning

confidence: 99%

Origins and Applications of London Dispersion Forces and Hamaker Constants in Ceramics

French

2000

Journal of the American Ceramic Society

263

100

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“…However, only one island is formed for an individual surface position at the triple junction. 15,26 In the present material, the islands involved a large number and almost covered the entire grain surface. On a microscopic scale, the growth of these domains seems to be reaction-controlled because of the kinked (100) surfaces.…”

Section: Discussionmentioning

confidence: 65%

Influences of intergranular precipitates on the structure and chemistry of interface in silicon nitride materials

Wang

Bando

et al. 2001

Surface & Interface Analysis

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Pure b-Si 3 N 4 is used in the present work as the starting powder to synthesize a-sialon (a ) ceramics; 5 wt.% a -seeds are added to promote nucleation of a-sialon. Transmission electron microscopy (TEM) observations reveal an inhomogeneous microstructure in which intergranular precipitates are produced in some regions where the structure and the chemistry of the interfaces vary significantly. The surfaces of the sialon grains adjacent to the precipitates are always rounded and corrugated, and the interfacial thickness increases. An internal band structure is usually discovered in these grains. Chemical analyses find that a small number of Y ions have been incorporated into the surface lattice. A possible formation mechanism of the corrugated surface is proposed and suggests a redissolution process of sialon grains during the crystallization of intergranular precipitates and an enhanced growth during cooling that is governed by interface-controlled kinetics. The increased number of growth sites eventually gives rise to a corrugated surface.

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“…For the 1.5 h-sample, large amount of elongated grains with high aspect ratio and homogeneous distribution could be achieved. The β-Si 3 N 4 seed crystals show a very slow growth rate of the prism planes, the grain diameter direction, in comparison to the growth rate of the basal plane, the grain length direction, which was due to the atomically "rough" basal plane [24]. However, further increase of dwell time (2 h) results in large diameter of β-Si 3 N 4 crystals.…”

Section: Experiments Proceduresmentioning

confidence: 96%