scholarly journals Строение специальных межкристаллитных границ в двухкомпонентных кристаллах

2019 ◽  
Vol 21 (4) ◽  
pp. 498-504
Author(s):  
Boris M. Darinskiy ◽  
Natalia D. Efanova ◽  
Andrey S. Prizhimov
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Analytical Method ◽  
Materials Science ◽  
Physical Review ◽  
Grain Boundary Engineering ◽  
Phase Boundaries ◽  
Acta Cryst ◽  
Cubic Crystals ◽  
Energy Applications

В настоящей работе представлена новая методика построения решетки совпадающих узлов для кристаллов простой кубической, ОЦК, ГЦК структур, имеющих моноэлементные и полиэлементные составы. Разработан метод нахождения атомов различных элементов в межкристаллитных границах на основе специально построенной кристаллографической группы. Указаны возможные элементные составы специальных межкристаллитных границ, зарядовые состояния сопрягающихся плоскостей         ЛИТЕРАТУРА1. Bollmann W. On the geometry of grain and phase boundaries // Phil. Mag., 1967, v. 16(140), pp. 363–381.DOI: https://doi.org/10.1080/147864367082297482. Bollmann W. On the geometry of grain and phase boundaries // Phil. Mag., 1967, v. 16(140), pp. 383–399.https://doi.org/10.1080/147864367082297493. Grimmer H. A method of determining the coincidence site lattices for cubic crystals // Acta Cryst. A,1974, v. 30(2), pp. 680–680. DOI: https://doi.org/10.1107/s056773947400163x4. Grimmer H., Bollmann W., Warrington D. T. Coincidence-site lattices and complete pattern-shiftin cubic crystals // Acta Cryst. A, 1974, v. 30(2), pp. 197–207. DOI : https://doi.org/10.1107/s056773947400043x5. Орлов А. Н., Перевезенцев В. Н., Рыбин В. В. Границы зерен в металлах. М.: Металлургия, 1980, 224 с.6. Глейтер Г., Чалмерс Б. Большеугловые границы зерен. М.: Мир, 1975, 376 с.7. Страумал Б. Б., Швиндлерман Л. С. Термическая стабильность и области существования специальных границ зерен // Поверхность. Физика, химия, механика, 1986, т. 10, с. 5–14.8. Fortes M. A. Coincidence site lattices in noncubic lattices // Phys. Stat. Sol. B, 1977, v. 82(1).pp. 377–382. DOI: https://doi.org/10.1002/pssb.22208201439. Bonnet R., Durand F. A general analytical method to fi nd a basis for the DSC lattice // ScriptaMet., 1975, v. 9(9), pp. 935–939. DOI: https://doi.org/10.1016/0036-9748(75)90548-710. Bonnet R. Note on a general analytical method to fi nd a basis for the DSC lattice. Derivation of a basisfor the CSL // Scripta Met., 1976, v. 10(9), pp. 801–806. DOI: https://doi.org/10.1016/0036-9748(76)90297-011. Bonnet R., Cousineau E. Computation of coincident and near-coincident cells for any two lattices– related DSC-1 and DSC-2 lattices // Acta Cryst. A, 1977, v. 33(5), pp. 850–856. DOI: https://doi.org/10.1107/s056773947700205812. Рыбин В. В., Перевезенцев В. Н. // ФТТ, 1975,т. 17, c. 3188–3193.13. Андреева А. В., Фионова Л. К. Анализ межкристаллитных границ на основе теории решетоксовпадающих узлов // ФММ, 1977, т. 44, с. 395–400.14. Кайбышев О. А., Валиев Р. З. Границы зерен и свойства металлов. М.: Металлургия, 1987, 214 c.15. Копецкий Ч. В., Орлов А. Н., Фионова Л. К. Границы зерен в чистых материалах. М.: Наука, 1987,160 c.16. Бокштейн Б. С. Структура и свойства внутренних поверхностей раздела в металлах. М.: Металлургия, 1988, 272 с.17. Kobayashi S., Tsurekawa S., Watanabe T. A new approach to grain boundary engineering for nanocrystallinematerials // Beilstein J. Nanotechnol., 2016, v. 7, pp. 1829–1849. DOI: https://doi.org/10.3762/bjnano.7.17618. Сухомлин Г. Д. Специальные границы в феррите низкоуглеродистых сталей // Металлофизика, новейшие технологии, 2013, т. 35, с. 1237–1249.19. Watanabe T. Grain boundary engineering: historical perspective and future prospects // Journalof Materials Science, 2011, v. 46, pp. 4095–4115. DOI: https://doi.org/10.1007/s10853-011-5393-z20. Waser R. Electronic properties of grain boundaries in SrTiO3 and BaTiO3 ceramics // Solid State Ionics,1995, v. 75, pp. 89–99. DOI: https://doi.org/10.1016/0167-2738(94)00152-i21. Daniels J., Wemicke R. New Aspects of an Improved PTC Model // Philips Res. Rep., 1976, v. 31,pp. 544–559.22. Vikrant K. S. N., Edwin G. R. Charged grain boundary transitions in ionic ceramics for energy applications// Computational Materials, 2019, v. 5(1), pp. 24. DOI: https://doi.org/10.1038/s41524-019-0159-223. Kim M., Duscher G., Browning N.D., Sohlberg K., Pantelides S. T., Pennycook S. J. Nonstoichiometryand the electrical activity of grain boundaries in SrTiO3 // Physical Review Letters, 2001, v. 86,pp. 4056–4059. DOI: https://doi.org/10.1103/physrevlett.86.405624. Oyama T., Wada N., Takagi H. Trapping of oxygen vacancy at grain boundary and its correlationwith local atomic confi guration and resultant excess energy in barium titanate: A systematic computationalanalysis // Physical Review B, 2010, v. 82, pp. 134107. DOI: https://doi.org/10.1103/physrevb.82.13410725. Duffy D.M., Tasker P.W. Space-charge regions around dipolar grain boundaries // Journal of AppliedPhysics, 1984, v. 56, pp. 971–977. DOI: https://doi.org/10.1063/1.33403726. Даринский Б. М., Ефанова Н. Д., Прижимов А. С. Систематика решеток совпадающих узловдля ОЦК и ГЦК кристаллов // Конденсированные среды и межфазные границы, 2018, т. 20(4), с. 581–586. DOI: https://doi.org/10.17308/kcmf.2018.20/632

Measurement of the Displacement Across a Coincidence Grain Boundary

1977 ◽  
Vol 35 ◽  
pp. 124-125
Author(s):  
J. W. Matthews ◽  
W. M. Stobbs
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Stacking Fault ◽  
The Other ◽  
Measuring Technique ◽  
High Angle ◽  
Twin Boundaries ◽  
Rigid Displacement ◽  
Cubic Crystals ◽  
Lattice Displacement

Many high-angle grain boundaries in cubic crystals are thought to be either coincidence boundaries (1) or coincidence boundaries to which grain boundary dislocations have been added (1,2). Calculations of the arrangement of atoms inside coincidence boundaries suggest that the coincidence lattice will usually not be continuous across a coincidence boundary (3). There will usually be a rigid displacement of the lattice on one side of the boundary relative to that on the other. This displacement gives rise to a stacking fault in the coincidence lattice.Recently, Pond (4) and Smith (5) have measured the lattice displacement at coincidence boundaries in aluminum. We have developed (6) an alternative to the measuring technique used by them, and have used it to find two of the three components of the displacement at {112} lateral twin boundaries in gold. This paper describes our method and presents a brief account of the results we have obtained.

Analytical Electron Microscopy And High-Resolution Electron Microscopy Studies Of Grain-Boundary Films In Silicon Nitride-Based Ceramics

1991 ◽  
Vol 238 ◽  
Author(s):  
H.-J. Kleebe ◽  
M. Rühle
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
Film Thickness ◽  
Grain Boundaries ◽  
Liquid Phase Sintering ◽  
Chemical Compositions ◽  
Phase Boundaries ◽  
Intergranular Films ◽  
Boundary Films

ABSTRACTThe microstructures of post-sintered reaction-bonded Si3N4 materials (SRBSN) were investigated. The materials consist of large elongated β-Si3N4 grains embedded in a finegrained matrix. Amorphous secondary phases exist at triple grain junctions owing to the liquid phase sintering involved during densificacition. Those amorphous phases can be crystallized (nearly completely) by post-sintering heat treatment. Apart from these crystalline grain pockets the grains of all materials are covered with thin (<l-2 nm) amorphous intergranular films on both Si3N4/Si3N4 grain boundaries as well as on secondary-phase/Si3N4 phase boundaries. A control of the intergranular films is most desirable since they limit the high-temperature mechanical properties of Si3N4-based ceramics. Therefore, the required characterization was performed by analytical and high-resolution transmission electron microscopy (AEM/HREM). Si3N4 materials with different rare-earth and transition-element oxide additions were studied. AEM and HREM investigations revealed marked differences in thicknesses and chemical compositions of the different intergranular films depending on the system analyzed indicating a strong dependence of film thickness on chemical composition. However, a given composition of each investigated material showed a characteristic intergranular film thickness, independent of grain misorientation, with the only exception of low-energy grain boundaries. The thickness of the intergranular films was constant within 0.2 nm. In addition, the film thickness of phase boundaries was always greater (by 1–2 nm) compared to grain-boundary films.

Anisotropic Behaviour of Grain Boundaries

2005 ◽  
Vol 482 ◽  
pp. 63-70 ◽  
Author(s):  
Václav Paidar ◽  
Pavel Lejček
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Polycrystalline Materials ◽  
Grain Boundary Engineering ◽  
Interfacial Dislocation ◽  
Special Character ◽  
Boundary Properties ◽  
Properties Of Materials ◽  
Boundary Classification ◽  
Boundary Chemistry

Grain boundaries are decisive for many properties of materials. Due to short-range stress field their influence is primarily based on their atomic structure. Special character of grain boundary properties related to their structure, follows from the nature of atomic arrangements in the boundary cores, from the interfacial dislocation content and from the boundary mobility. All those aspects of boundary behaviour are strongly influenced by the boundary chemistry including various segregation phenomena. Approaches to the boundary classification and the interpretation of recent experimental results are discussed in the context of the complex relationship between microstructure and material properties. Such findings are essential for Grain Boundary Engineering proposed to improve the performance of polycrystalline materials.

Grain-Boundary Segregation and Phase-Separation Mechanism in Yttria-Stabilized Tetragonal Zirconia Polycrystal

2011 ◽  
Vol 484 ◽  
pp. 82-88
Author(s):  
Koji Matsui ◽  
Hidehiro Yoshida ◽  
Yuichi Ikuhara
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Segregation ◽  
Grain Boundary Segregation ◽  
Cubic Phase ◽  
Phase Boundaries ◽  
Transmission Electron ◽  
Sintering Condition

Microstructure development during sintering in 3 mol% Y2O3-stabilized tetragonal ZrO2 polycrystal (Y-TZP) was systematically investigated in two sintering conditions: (a) 1100-1650°C for 2 h and (b) 1300°C for 0-50 h. In the sintering condition (a), the density and grain size in Y-TZP increased with the increasing sintering temperature. Scanning transmission electron microscopy (STEM) and nanoprobe X-ray energy dispersive spectroscopy (EDS) measurements revealed that the Y3+ ion distribution was nearly homogeneous up to 1300°C, i.e., most of grains were the tetragonal phase, but cubic-phase regions with high Y3+ ion concentration were clearly formed in grain interiors adjacent to the grain boundaries at 1500°C. High-resolution transmission electron microscopy (HRTEM) and nanoprobe EDS measurements revealed that no amorphous or second phase is present along the grain-boundary faces, and Y3+ ions segregated not only along the tetragonal-tetragonal phase boundaries but also along tetragonal-cubic phase boundaries over a width below about 10 nm, respectively. These results indicate that the cubic-phase regions are formed from the grain boundaries and/or the multiple junctions in which Y3+ ions segregated. We termed this process a “grain boundary segregation-induced phase transformation (GBSIPT)” mechanism. In the sintering condition (b), the density was low and the grain-growth rate was much slow. In the specimen sintered at 1300°C for 50 h, the cubic-phase regions were clearly formed in the grain interiors adjacent to the grain boundaries. This behavior shows that the cubic-phase regions were formed without grain growth, which can be explained by the GBSIPT model.

Improvement of thermoelectric performance of Bi2Te2.7Se0.3 via grain boundary engineering with melting KOH

2019 ◽  
Vol 12 (06) ◽  
pp. 1950082 ◽  
Author(s):  
Tingyang Liu ◽  
Weiming Zhu ◽  
Rui Wang ◽  
Shuankui Li ◽  
Yinguo Xiao
Keyword(s):  
Thermal Conductivity ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Weight Percent ◽  
Phonon Transport ◽  
Liquid Phase Sintering ◽  
Homogeneous Distribution ◽  
Grain Boundary Engineering ◽  
Sintering Process ◽  
Simple Method

Grain boundary engineering is considered an effective approach to improve the performance of thermoelectric materials. Herein, by introducing KOH into the grain boundary of Bi2[Formula: see text][Formula: see text] (BTS) via liquid phase sintering strategy, the thermoelectric performances are improved significantly. The melting KOH spreads over the grain boundaries during the high temperature sintering process, which could be used to optimize the carrier/phonon transport behavior. The maximum ZT reaches up to 0.97 for the sample incorporated with 0.5%[Formula: see text]Wt of KOH at 425[Formula: see text]K, which achieves 30% improvement over the pure BTS. The homogeneous distribution of KOH layer on the grain boundaries forms efficient potential barrier scattering, which increases power factor and reduces thermal conductivity simultaneously. Particularly, it is found that the maximum ZT can be tuned gradually in the temperature range from 450[Formula: see text]K to 375[Formula: see text]K by tuning the weight percent of KOH, demonstrating a possibility in adjusting the thermoelectric properties of BTS using a relatively simple method.

Grain Boundary Engineering: Progress and Challenges

2007 ◽  
Vol 539-543 ◽  
pp. 3389-3394 ◽  
Author(s):  
Wei Guo Wang
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Electron Backscatter Diffraction ◽  
Coincidence Site Lattice ◽  
Grain Boundary Character Distribution ◽  
Grain Boundary Engineering ◽  
Special Boundaries ◽  
Grain Boundary Character ◽  
Proposed Model ◽  
Backscatter Diffraction

The progress of grain boundary engineering (GBE) is overviewed and the challenges for further investigations emphasized. It points out that, the electron backscatter diffraction (EBSD) reconstruction of grain boundaries, which gives the information of connectivity interruption of general high angle boundaries (HABs), is more significant than purely pursuing high frequency of so-called special boundaries. The criterion for the optimization of grain boundary character distribution (GBCD) needs to be established. The energy spectrum and the degradation susceptibility of grain boundaries of various characters including HABs and low Σ（Σ≤29） coincidence site lattice (CSL) needs to be studied and ascertained. And finally, the newly proposed model of non-coherent Σ3 interactions for GBCD optimization are discussed.

Grain Boundary Engineering by Application of Mechanical Stresses

2007 ◽  
Vol 558-559 ◽  
pp. 987-992
Author(s):  
Myrjam Winning
Keyword(s):  
Stress Field ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Mechanical Stress ◽  
Grain Growth ◽  
Microstructure Evolution ◽  
Mechanical Stresses ◽  
Grain Boundary Engineering ◽  
New Approach ◽  
Kinetics Of

It is shown that an externally applied mechanical stress field can change the kinetics of individual grain boundaries. Moreover, such mechanical stresses also have influence on grain growth and recrystallization kinetics and can strongly affect the microstructure evolution, so that the application of mechanical stresses during annealing can be used as a new approach in the field of grain boundary engineering.

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