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Showing papers on "Grain boundary published in 2010"


Journal ArticleDOI
TL;DR: In this paper, single-crystal graphene grains synthesized by ambient CVD on polycrystalline Cu are studied and individual boundaries between coalescing grains affect graphene's electronic properties.
Abstract: The strong interest in graphene has motivated the scalable production of high quality graphene and graphene devices. Since large-scale graphene films synthesized to date are typically polycrystalline, it is important to characterize and control grain boundaries, generally believed to degrade graphene quality. Here we study single-crystal graphene grains synthesized by ambient CVD on polycrystalline Cu, and show how individual boundaries between coalescing grains affect graphene's electronic properties. The graphene grains show no definite epitaxial relationship with the Cu substrate, and can cross Cu grain boundaries. The edges of these grains are found to be predominantly parallel to zigzag directions. We show that grain boundaries give a significant Raman "D" peak, impede electrical transport, and induce prominent weak localization indicative of intervalley scattering in graphene. Finally, we demonstrate an approach using pre-patterned growth seeds to control graphene nucleation, opening a route towards scalable fabrication of single-crystal graphene devices without grain boundaries.

1,294 citations


Journal ArticleDOI
08 Apr 2010-Nature
TL;DR: It is shown that dislocation nucleation governs the strength of nano-twinned materials, resulting in their softening below a critical twin thickness, and the critical twin-boundary spacing and the maximum strength depend on the grain size.
Abstract: In conventional metals, there is plenty of space for dislocations-line defects whose motion results in permanent material deformation-to multiply, so that the metal strengths are controlled by dislocation interactions with grain boundaries(1,2) and other obstacles(3,4). For nano-structured materials, in contrast, dislocation multiplication is severely confined by the nanometre-scale geometries so that continued plasticity can be expected to be source-controlled. Nano-grained polycrystalline materials were found to be strong but brittle(5-9), because both nucleation and motion of dislocations are effectively suppressed by the nanoscale crystallites. Here we report a dislocation-nucleation-controlled mechanism in nano-twinned metals(10,11) in which there are plenty of dislocation nucleation sites but dislocation motion is not confined. We show that dislocation nucleation governs the strength of such materials, resulting in their softening below a critical twin thickness. Large-scale molecular dynamics simulations and a kinetic theory of dislocation nucleation in nano-twinned metals show that there exists a transition in deformation mechanism, occurring at a critical twin-boundary spacing for which strength is maximized. At this point, the classical Hall-Petch type of strengthening due to dislocation pile-up and cutting through twin planes switches to a dislocation-nucleation-controlled softening mechanism with twin-boundary migration resulting from nucleation and motion of partial dislocations parallel to the twin planes. Most previous studies(12,13) did not consider a sufficient range of twin thickness and therefore missed this strength-softening regime. The simulations indicate that the critical twin-boundary spacing for the onset of softening in nano-twinned copper and the maximum strength depend on the grain size: the smaller the grain size, the smaller the critical twin-boundary spacing, and the higher the maximum strength of the material.

924 citations


Journal ArticleDOI
26 Mar 2010-Science
TL;DR: Simulations show that grain boundaries in copper can act as sinks for radiation-induced defects, and find thatgrain boundaries have a surprising “loading-unloading” effect.
Abstract: Although grain boundaries can serve as effective sinks for radiation-induced defects such as interstitials and vacancies, the atomistic mechanisms leading to this enhanced tolerance are still not well understood With the use of three atomistic simulation methods, we investigated defect-grain boundary interaction mechanisms in copper from picosecond to microsecond time scales We found that grain boundaries have a surprising "loading-unloading" effect Upon irradiation, interstitials are loaded into the boundary, which then acts as a source, emitting interstitials to annihilate vacancies in the bulk This unexpected recombination mechanism has a much lower energy barrier than conventional vacancy diffusion and is efficient for annihilating immobile vacancies in the nearby bulk, resulting in self-healing of the radiation-induced damage

876 citations


Journal ArticleDOI
TL;DR: A survey of previous work related to the relationship between grain size and corrosion resistance for a number of light metamodel classes can be found in this article, with a focus on the effect of grain size on corrosion.
Abstract: Grain refinement is known to lead to improvements in strength and wear resistance. Inherent processing involved in grain refinement alter both the bulk and the surface of a material, leading to changes in grain boundary density, orientation, and residual stress. Ultimately, these surface changes can have an impact on electrochemical behavior and, consequently, corrosion susceptibility as evidenced by the large number of studies on the effect of grain size on corrosion, which span a range of materials and test environments. However, there has been limited work on developing a fundamental understanding of how grain refinement and more generally how grain size affects the corrosion resistance of an alloy. Existing literature is often contradictory, even within the same alloy class, and a coherent understanding of how grain size influences corrosion response is largely lacking. A survey of previous work related to the relationship between grain size and corrosion resistance for a number of light meta...

873 citations


Journal ArticleDOI
TL;DR: This work develops a theory of charge carrier transmission through grain boundaries composed of a periodic array of dislocations in graphene based on the momentum conservation principle and sheds light on the transport properties of large-area graphene samples.
Abstract: Most materials in available macroscopic quantities are polycrystalline. Graphene, a recently discovered two-dimensional form of carbon with strong potential for replacing silicon in future electronics, is no exception. There is growing evidence of the polycrystalline nature of graphene samples obtained using various techniques. Grain boundaries, intrinsic topological defects of polycrystalline materials, are expected to markedly alter the electronic transport in graphene. Here, we develop a theory of charge carrier transmission through grain boundaries composed of a periodic array of dislocations in graphene based on the momentum conservation principle. Depending on the grain-boundary structure we find two distinct transport behaviours--either high transparency, or perfect reflection of charge carriers over remarkably large energy ranges. First-principles quantum transport calculations are used to verify and further investigate this striking behaviour. Our study sheds light on the transport properties of large-area graphene samples. Furthermore, purposeful engineering of periodic grain boundaries with tunable transport gaps would allow for controlling charge currents without the need to introduce bulk bandgaps in otherwise semimetallic graphene. The proposed approach can be regarded as a means towards building practical graphene electronics.

839 citations


Journal ArticleDOI
12 Nov 2010-Science
TL;DR: Using atomistic calculations, graphene sheets with large-angle tilt boundaries that have a high density of defects are as strong as the pristine material and, unexpectedly, are much stronger than those with low-angle boundaries having fewer defects.
Abstract: Graphene in its pristine form is one of the strongest materials tested, but defects influence its strength. Using atomistic calculations, we find that, counter to standard reasoning, graphene sheets with large-angle tilt boundaries that have a high density of defects are as strong as the pristine material and, unexpectedly, are much stronger than those with low-angle boundaries having fewer defects. We show that this trend is not explained by continuum fracture models but can be understood by considering the critical bonds in the strained seven-membered carbon rings that lead to failure; the large-angle boundaries are stronger because they are able to better accommodate these strained rings. Our results provide guidelines for designing growth methods to obtain sheets with strengths close to that of pristine graphene.

767 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that yttrium-stabilized zirconia can be sintered in a few seconds at ∼850°C to full density, starting from a green density of 0.5, by the application of a dc electrical field.
Abstract: We show that yttrium-stabilized zirconia can be sintered in a few seconds at ∼850°C to full density, starting from a green density of 0.5, by the application of a dc electrical field (nominally, several hours at 1450°C are needed to complete the sintering process). This finding is explained by the local Joule heating at grain boundaries, which, on the one hand, promotes grain-boundary diffusion (a kinetic effect), while at the same time restricts grain growth (a thermodynamic effect). The smaller grain size and the higher temperature at grain boundaries can then act synergistically to enhance the rate of sintering. These results have a bearing in explaining the widespread spark plasma and microwave-assisted techniques for enhanced sintering.

751 citations


Journal ArticleDOI
TL;DR: In this paper, a review of the pertinent literature combined with the authors' works reveals that a relationship exists between corrosion rate and grain size and reveals an important fundamental relationship that can be exploited for material durability and design.

707 citations


Journal ArticleDOI
TL;DR: In this article, the authors introduce a general approach for constructing dislocations in graphene characterized by arbitrary Burgers vectors as well as grain boundaries, covering the whole range of possible misorientation angles.
Abstract: Topological defects in graphene, dislocations and grain boundaries, are still not well understood despite the considerable number of experimental observations. We introduce a general approach for constructing dislocations in graphene characterized by arbitrary Burgers vectors as well as grain boundaries, covering the whole range of possible misorientation angles. By using ab initio calculations we investigate thermodynamic and electronic properties of these topological defects, finding energetically favorable symmetric large-angle grain boundaries, strong tendency toward out-of-plane deformation in the small-angle regimes, and pronounced effects on the electronic structure. The present results show that dislocations and grain boundaries are important intrinsic defects in graphene which may be used for engineering graphene-based nanomaterials and functional devices.

628 citations


Journal ArticleDOI
TL;DR: In this article, the effect of grain size and grain orientation on deformation twinning in a Fe-22-wt.% Mn-0.6-c TWIP steel was investigated.
Abstract: We investigate the effect of grain size and grain orientation on deformation twinning in a Fe–22 wt.% Mn–0.6 wt.% C TWIP steel using microstructure observations by electron channeling contrast imaging (ECCI) and electron backscatter diffraction (EBSD). Samples with average grain sizes of 3 μm and 50 μm were deformed in tension at room temperature to different strains. The onset of twinning concurs in both materials with yielding which leads us to propose a Hall–Petch-type relation for the twinning stress using the same Hall–Petch constant for twinning as that for glide. The influence of grain orientation on the twinning stress is more complicated. At low strain, a strong influence of grain orientation on deformation twinning is observed which fully complies with Schmid's law under the assumption that slip and twinning have equal critical resolved shear stresses. Deformation twinning occurs in grains oriented close to 〈1 1 1〉//tensile axis directions where the twinning stress is larger than the slip stress. At high strains (0.3 logarithmic strain), a strong deviation from Schmid's law is observed. Deformation twins are now also observed in grains unfavourably oriented for twinning according to Schmid's law. We explain this deviation in terms of local grain-scale stress variations. The local stress state controlling deformation twinning is modified by local stress concentrations at grain boundaries originating, for instance, from incoming bundles of deformation twins in neighboring grains.

567 citations


Journal ArticleDOI
TL;DR: The spatial variation of lithium-ion diffusion times in the battery-cathode material LiCoO(2) is probed at a resolution of ∼100 nm by using an atomic force microscope to both redistribute lithium ions and measure the resulting cathode deformation, revealing that the diffusion coefficient increases for certain grain orientations and single-grain boundaries.
Abstract: The movement of lithium ions into and out of electrodes is central to the operation of lithium-ion batteries. Although this process has been extensively studied at the device level, it remains insufficiently characterized at the nanoscale level of grain clusters, single grains and defects. Here, we probe the spatial variation of lithium-ion diffusion times in the battery-cathode material LiCoO(2) at a resolution of ∼100 nm by using an atomic force microscope to both redistribute lithium ions and measure the resulting cathode deformation. The relationship between diffusion and single grains and grain boundaries is observed, revealing that the diffusion coefficient increases for certain grain orientations and single-grain boundaries. This knowledge provides feedback to improve understanding of the nanoscale mechanisms underpinning lithium-ion battery operation.

Journal Article
TL;DR: In this paper, a general approach for constructing dislocations in graphene characterized by arbitrary Burgers vectors as well as grain boundaries, covering the whole range of possible misorientation angles, is introduced.
Abstract: Topological defects in graphene, dislocations and grain boundaries, are still not well understood despites the considerable number of experimental observations. We introduce a general approach for constructing dislocations in graphene characterized by arbitrary Burgers vectors as well as grain boundaries, covering the whole range of possible misorientation angles. By using ab initio calcula- tions we investigate thermodynamic and electronic properties of these topological defects, finding energetically favorable symmetric large-angle grain boundaries, strong tendency towards out-of- plane deformation in the small-angle regimes, and pronounced effects on the electronic structure. The present results show that dislocations and grain boundaries are important intrinsic defects in graphene which may be used for engineering graphene-based nanomaterials and functional devices.

Journal ArticleDOI
TL;DR: The fabrication of BaZr(0.8)Y (BZY) proton-conducting electrolyte thin films by pulsed laser deposition on different single-crystalline substrates shows the largest proton conductivity ever reported for BZY samples, and opens new potential for the development of miniaturized SOFCs for portable power supply.
Abstract: R educing the operating temperature in the 500‐750 C range is needed for widespread use of solid oxide fuel cells (SOFCs). Proton-conducting oxides are gaining wide interest as electrolyte materials for this aim. We report the fabrication of BaZr0:8Y0:2O3 (BZY) proton-conducting electrolyte thin films by pulsed laser deposition on different single-crystalline substrates. Highly textured, epitaxially oriented BZY films were obtained on (100)-oriented MgO substrates, showing the largest proton conductivity ever reported for BZY samples, being 0:11 S cm 1 at 500 C. The excellent crystalline quality of BZY films allowed for the first time the experimental measurement of the large BZY bulk conductivity above 300 C, expected in the absence of blocking grain boundaries. The measured proton conductivity is also significantly larger than the conductivity values of oxygen-ion conductors in the same temperature range, opening new potential for the development of miniaturized SOFCs for portable power supply.

Journal ArticleDOI
TL;DR: This paper conducted a statistical analysis on large data sets generated by electron backscattering diffraction (EBSD) to extract quantitative and meaningful relationships between material microstructure and deformation twinning in magnesium.
Abstract: To extract quantitative and meaningful relationships between material microstructure and deformation twinning in magnesium, we conduct a statistical analysis on large data sets generated by electron backscattering diffraction (EBSD). The analyses show that not all grains of similar orientation and grain size form twins, and twinning does not occur exclusively in grains with high twin Schmid factors or in the relatively large grains of the sample. The number of twins per twinned grain increases with grain area, but twin thickness and the fraction of grains with at least one visible twin are independent of grain area. On the other hand, an analysis of twin pairs joined at a boundary indicates that grain boundary misorientation angle strongly influences twin nucleation and growth. These results question the use of deterministic rules for twin nucleation and Hall–Petch laws for size effects on twinning. Instead, they encourage an examination of the defect structures of grain boundaries and their role in twin ...

Book
31 Jul 2010
TL;DR: In this paper, the authors discuss the relationship between grain boundaries and non-equilibrium grain boundary segregation, including the effect of variables on equilibrium grain boundary separation and its relationship with metallurgical phenomena.
Abstract: I Introduction II Grain boundaries: structure, description and thermodynamics III Approaches to Study Grain Boundary Segregation IV Models of Equilibrium Grain Boundary Segregation V Effect of Variables on Equilibrium Grain Boundary Segregation VI Principles of Non-Equilibrium Segregation VII Grain Boundary Segregation and Related Phenomena and metallurgical phenomena VIII Concluding remarks

Journal ArticleDOI
TL;DR: In this article, a comparative study and Raman characterization of the formation of graphene on single crystal Ni (111) and polycrystalline Ni substrates using chemical vapor deposition (CVD) was performed.
Abstract: We report a comparative study and Raman characterization of the formation of graphene on single crystal Ni (111) and polycrystalline Ni substrates using chemical vapor deposition (CVD). Preferential formation of monolayer/bilayer graphene on the single crystal surface is attributed to its atomically smooth surface and the absence of grain boundaries. In contrast, CVD graphene formed on polycrystalline Ni leads to a higher percentage of multilayer graphene (≥3 layers), which is attributed to the presence of grain boundaries in Ni that can serve as nucleation sites for multilayer growth. Micro-Raman surface mapping reveals that the area percentages of monolayer/bilayer graphene are 91.4% for the Ni (111) substrate and 72.8% for the polycrystalline Ni substrate under comparable CVD conditions. The use of single crystal substrates for graphene growth may open ways for uniform high-quality graphene over large areas.

Journal ArticleDOI
TL;DR: In this article, the micro-structural evolution and grain refinement in ANSI 304 stainless steel subjected to multiple laser shock processing (LSP) impacts were investigated by means of cross-sectional optical microscopy and transmission electron microscopy observations.

Journal ArticleDOI
TL;DR: A comparative study of the effectiveness of Y, La, Ce and Gd as texture modifiers during the extrusion of magnesium-based alloys has been carried out in this paper, where it was found that Y was not as effective as the other three elements in modifying the texture, and at no concentration studied did this element form a typical rare earth texture.
Abstract: A comparative study of the effectiveness of Y, La, Ce and Gd as texture modifiers during the extrusion of magnesium-based alloys has been carried out. It was found that La, Ce and Gd are all effective texture modifiers, being able to produce the “rare earth” texture at the low alloying levels of 300, 400 and 600 ppm respectively. Y was not as effective as the other three elements in modifying the texture, and at no concentration studied did this element form a typical “rare earth” texture. It is proposed that a strong interaction of solutes with dislocations and grain boundaries is responsible for the significant impact rare earth additions have on the extruded grain size and texture at very low alloying levels.

Journal ArticleDOI
TL;DR: In this article, the plastic deformation behavior and the effects of the impact time on the LY2 aluminum (Al) alloy during multiple laser shock processing (LSP) impacts were investigated.

Journal ArticleDOI
TL;DR: Analysis shows that two-dimensional nature permits the off-plane relaxation, unavailable in three-dimensional materials, qualitatively reducing the energy of defects on one hand while forming stable 3D landscapes on the other.
Abstract: A polycrystalline graphene consists of perfect domains tilted at angle α to each other and separated by the grain boundaries (GB). These nearly one-dimensional regions consist in turn of elementary topological defects, 5-pentagons and 7-heptagons, often paired up into 5−7 dislocations. Energy G(α) of GB computed for all range 0 ≤ α ≤ π/3, shows a slightly asymmetric behavior, reaching ∼5 eV/nm in the middle, where the 5′s and 7′s qualitatively reorganize in transition from nearly armchair to zigzag interfaces. Analysis shows that two-dimensional (2D) nature permits the off-plane relaxation, unavailable in three-dimensional (3D) materials, qualitatively reducing the energy of defects on one hand while forming stable 3D landscapes on the other. Interestingly, while the GB display small off-plane elevation, the random distributions of 5′s and 7′s create roughness that scales inversely with defect concentration, h ∼ n−1/2.

Journal ArticleDOI
TL;DR: In this article, a large strain warm deformation at different temperatures and subsequent intercritical annealing has been applied to obtain fine grained (2.4m) and ultrafine-grained (1.2m) ferrite/martensite dual-phase (DP) steels.
Abstract: Large strain warm deformation at different temperatures and subsequent intercritical annealing has been applied to obtain fine grained (2.4m) and ultrafine grained (1.2m) ferrite/martensite dual-phase (DP) steels. Their mechanical properties were tested under tensile and impact conditions and compared to a hot deformed coarse grained (12.4m) reference material. Both yield strength and tensile strength follow a Hall–Petch type linear relationship, whereas uniform elongation and total elongation are hardly affected by grain refinement. The initial strain hardening rate as well as the post-uniform elongation increase with decreasing grain size. Ductile fracture mechanisms are considerably promoted due to grain refinement. Grain refinement further lowers the ductile-to-brittle transition temperature and leads to higher absorbed impact energies. Besides the common correlations with the ferrite grain size, these phenomena are explained in terms of the martensite particle size, shape and distribution and the more homogeneous dislocation distribution in ultrafine ferrite grains.

Journal ArticleDOI
TL;DR: In this article, a pin-on-disk wear testing of nanocrystalline Ni-W alloys with grain sizes of 3-47nm has been carried out and the extreme conditions produced during sliding wear are found to result in structural evolution and a deviation from Archard scaling for the finest grain sizes; in the finest nanocrystine materials wear resistance is higher than would be expected based on hardness alone.

Journal ArticleDOI
TL;DR: In this paper, the effect of industrial pre-treatment on the corrosion performance of Mg alloy AZ31 sheet was investigated, and it was found that tempering accelerates the corrosion of AZ31.

Journal ArticleDOI
TL;DR: In this paper, high-pressure torsion alloys were found to exhibit a very high strength, considerably exceeding the Hall-Petch predictions for ultrafine grains, which was attributed to the unique combination of ultrafine structure and deformation-induced segregations of solute elements along grain boundaries, which may affect the emission and mobility of intragranular dislocations.

Journal ArticleDOI
TL;DR: It is shown, through time-resolved terahertz spectroscopy, that low mobility in polycrystalline TiO(2) nanotubes is not due to scattering from grain boundaries or disorder-induced localization as in other nanomaterials, but instead results from a single sharp resonance arising from exciton-like trap states.
Abstract: Nanoparticle films have become a promising low-cost, high-surface-area electrode material for solar cells and solar fuel production. Compared to sintered nanoparticle films, oriented polycrystalline titania nanotubes offer the advantage of directed electron transport, and are expected to have higher electron mobility. However, macroscopic measurements have revealed their electron mobility to be as low as that of nanoparticle films. Here, we show, through time-resolved terahertz spectroscopy, that low mobility in polycrystalline TiO(2) nanotubes is not due to scattering from grain boundaries or disorder-induced localization as in other nanomaterials, but instead results from a single sharp resonance arising from exciton-like trap states. If the number of these states can be lowered, this could lead to improved electron transport in titania nanotubes and significantly better solar cell performance.

Journal ArticleDOI
TL;DR: In this paper, a correlation between the initial open-circuit potential of fresh brittle intergranular fracture surfaces, the copper content of grain-boundary precipitates (GBP), and the plateau SCC velocities of overaged 7079 and 7075 alloys was found.

Journal ArticleDOI
TL;DR: In this paper, the authors summarize the progress made recently in understanding the electronic structure of chalcopyrite solar cells and summarize the results of optoelectronic defect spectroscopy.
Abstract: We summarize the progress made recently in understanding the electronic structure of chalcopyrites. New insights into the dispersion of valence and conduction band allow conclusions on the effective masses of charge carriers and their orientation dependence, which influences the transport in solar cell absorbers of different orientation. Native point defects are responsible for the doping and thus the band bending in solar cells. Results of optoelectronic defect spectroscopy are reviewed. Native defects are also the source for a number of metastabilities, which strongly affect the efficiency of solar cells. Recent theoretical findings relate these effects to the Se vacancy and the InCu antisite defect. Experimentally determined activation energies support these models. Absorbers in chalcopyrite solar cells are polycrystalline, which is only possible because of the benign character of the grain boundaries. This can be related to an unusual electronic structure of the GB. Copyright © 2010 John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: In this article, the role of strain transfer in the activation of deformation twinning at grain boundaries has been characterized in commercially pure titanium deformed in bending and two different orientations of a textured polycrystal were analyzed using electron backscattered diffraction (EBSD) to determine the active slip and twinning systems in the surface tensile region.
Abstract: The role of strain transfer in the activation of deformation twinning at grain boundaries has been characterized in commercially pure titanium deformed in bending. Two different orientations of a textured polycrystal were deformed in bending and were analyzed using electron backscattered diffraction (EBSD) to determine the active slip and twinning systems in the surface tensile region. Prismatic slip and $$ \left\{ {10\bar{1}2} \right\}\left\langle {\bar{1}011} \right\rangle $$ twinning were the most widely observed deformation modes in both orientations. Nonprismatic slip systems were also activated, most likely to accommodate local strain heterogeneities. A slip-stimulated twin nucleation mechanism was identified for soft/hard grain pairs: dislocation slip in a soft-oriented grain can stimulate twin nucleation in the neighboring hard grain when the slip system is well aligned with the twinning system. This alignment was described by a slip-transfer parameter m′.[24] Twins activated by this mechanism always had the highest m′ value among the six available $$ \left\{ {10\bar{1}2} \right\}\left\langle {\bar{1}011} \right\rangle $$ twinning systems, while the Schmid factor, based on the global (uniaxial tensile) stress state, was a less significant indicator of twin activity. Through slip transfer, deformation twins sometimes formed despite having a very low global Schmid factor. The frequency of slip-stimulated twin nucleation depends strongly on the texture and loading direction in the material. For grain pairs having one grain with a large Schmid factor for twinning, nonparametric statistical analysis confirms that those with a larger m′ are more likely to display slip-stimulated twinning.

Journal ArticleDOI
TL;DR: Sintering occurs when packed particles are heated to a temperature where there is sufficient atomic motion to grow bonds between the particles as mentioned in this paper, and the conditions that induce sintering depend on the material, its melting temperature, particle size, and a host of processing variables.
Abstract: Sintering occurs when packed particles are heated to a temperature where there is sufficient atomic motion to grow bonds between the particles The conditions that induce sintering depend on the material, its melting temperature, particle size, and a host of processing variables It is common for sintering to produce a dimensional change, typically shrinkage, where the powder compact densifies, leading to significant strengthening Microstructure coarsening is inherent to sintering, most evident as grain growth, but it is common for pore growth to occur as density increases During coarsening, the grain structure converges to a self-similar character seen in both the grain shape distribution and grain size distribution Coarsening behavior during sintering conforms to classic grain growth kinetics, modified to reflect the evolving microstructure These modifications involve the grain boundary coverage due to pores, liquid films, or second phases and the altered grain boundary mobility due to these phases

Journal ArticleDOI
TL;DR: In this article, the specific grain interior and grain boundary conductivities, obtained from impedance spectroscopy and the brick layer model, are reported for BaZr 0.9 Y 0.1 O 3 − δ as a function of p O 2 and temperature.