Effect of Crystal Lattice Microstrain on the Parameters of Grain-Boundary Ensembles in Alloys with L12 Superstructure

2021 ◽  
Vol 85 (9) ◽  
pp. 1022-1025
Author(s):  
E. V. Konovalova ◽  
O. B. Perevalova
Keyword(s):  
Grain Boundary ◽  
Crystal Lattice ◽  
Lattice Microstrain

scholarly journals Some electrophysical properties of polycrystalline silicon obtained in a solar oven

2021 ◽  
Author(s):  
Lutfiddin Omanovich Olimov ◽  
Iqboljon Anarboyev
Keyword(s):  
Grain Boundary ◽  
Crystal Lattice ◽  
Thermoelectric Materials ◽  
Polycrystalline Silicon ◽  
Specific Resistance ◽  
Charge Carriers ◽  
Barrier Effect ◽  
Electrophysical Properties ◽  
Recombination Centers ◽  
Thermal Vibrations

Abstract The article describes the results of the study of the microstructure and some electrophysical properties of silicon obtained by re-melting in a solar oven. It was found that the granularity of polycrystalline silicon consists of Si atoms with a size of 10–15 µm, the roughness of its surface. Decrease in specific resistance at T≤600 K, increase in concentration of ionized input atoms and concentration of charge carriers, the position at Т∼600 ÷ 700 K is based on the decrease in the free path of the charge carriers as a result of thermal vibrations of the crystal lattice, the situation at T ≥ 700 K K was explained by the emergence of new recombination centers specific to localized traps. Polycrystalline silicon heated by sunlight does not create a barrier effect of traps localized in the grain boundary regions from polycrystalline silicon obtained by other methods. This can expand the possibilities of creating highly efficient semiconductor devices, solar cells, thermoelectric materials for micro- and nanoelectronics, photovoltaics.

Deformation of a [001] Σ13 grain boundary in silicon

1992 ◽  
Vol 50 (1) ◽  
pp. 250-251
Author(s):  
Laurent Sagalowicz ◽  
William A. T. Clark
Keyword(s):  
Mechanical Properties ◽  
Grain Boundary ◽  
Crystal Lattice ◽  
Grain Boundaries ◽  
Important Influence ◽  
Polycrystalline Materials ◽  
Symmetrical Loading

The interaction between crystal lattice dislocations and grain boundaries has an important influence on the mechanical properties of polycrystalline materials. We describe here a study of the behavior of the Σ13, (510)1, 22.67°/[001] grain boundary in Si, deformed under symmetrical loading. The dissociation of crystal lattice dislocations which interact with this boundary during deformation is far more complicated than simple geometrical models predict.

Dislocation Reactions at Grain Boundaries in Li2 Ordered Alloys

1986 ◽  
Vol 81 ◽  
Author(s):  
A.H. King ◽  
M.H. Yoo
Keyword(s):  
Grain Boundary ◽  
Crystal Lattice ◽  
Grain Boundaries ◽  
Chemical Ordering ◽  
Ordered Alloys

AbstractThe characteristics of perfect grain boundary dislocations in ordered alloys are discussed, and consideration is given to the possible formation of perfect and imperfect grain boundary dislocations by the impingement of crystal lattice dislocations. It is shown that many dislocation reactions at grain boundaries in ordered alloys are made unfavorableif chemical co—ordination must be maintained in the structure of the grain boundary. This leads to a suggestion that the effect of boron in the grain boundaries of Ni3AI is to reduce the importance of chemical ordering, and thus to promote deformation by allowing greater freedom for dislocation reactions to occur.

Dislocation Dissociation in the Σ13 Grain Boundary in Silicon

1991 ◽  
Vol 238 ◽  
Author(s):  
Laurent Sagalowicz ◽  
Richard Beanland ◽  
William A. T. Clark
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Boundary ◽  
Crystal Lattice ◽  
Dislocation Structure ◽  
Alternative Structures ◽  
Transmission Electron ◽  
Dislocation Dissociation

ABSTRACTTransmission electron microscopy has been used to study the atomic and dislocation structure of deformed and undeformed Σ13 {510} boundary in Si. It is shown that there are several alternative structures for this boundary, which may be separated by imperfect and partial grain boundary dislocations. It is also shown that the dissociation of crystal lattice dislocations which interact with the boundary during deformation results is far more complicated than simple geometrical models applicable in monatomic materials predicts.

scholarly journals A method for extracting crystal grain boundary using three-dimensional crystal lattice model

2009 ◽  
Vol 29-1 (2) ◽  
pp. 1103-1103
Author(s):  
Tomoko ENDO ◽  
Naomichi SAKAMOTO ◽  
Takuya YASUNO ◽  
Naoki MUKAWA
Keyword(s):  
Grain Boundary ◽  
Crystal Lattice ◽  
Lattice Model ◽  
Three Dimensional ◽  
Dimensional Crystal

Primary and Secondary Grain Boundary Dislocations in Symmetric Tilt Grain Boundaries of Finite Length

1998 ◽  
Vol 538 ◽  
Author(s):  
Annamalai Lakshmanan ◽  
Alexander H. King
Keyword(s):  
Free Surface ◽  
Grain Boundary ◽  
Crystal Lattice ◽  
Grain Boundaries ◽  
Finite Length ◽  
Large Angle ◽  
Symmetric Tilt ◽  
The Creation ◽  
Meso Scale

AbstractSecondary grain boundary dislocations in large-angle grain boundaries (also called dsc-dislocations) can be described as local variations in the density of the primary (or lattice) dislocations that make up the boundary. We present a simple meso-scale simulation in which the interactions of primary dislocations with each other and with the crystal lattice produce secondary dislocations with smaller Burgers vectors and larger spacing. We use the model to explore the interactions of the primary and secondary defects with a free surface terminating the grain boundary, and demonstrate cases in which the primary dislocations dominate the interactions, forcing the secondary dislocations to increase their energy. Other cases are found, for which all of the dislocations can respond in such a way that their energy decreases. The creation of interfacial disclinations is also demonstrated.

Saturation Effect of Al(NO3)3 Dopant on Residual Voltages of ZnO Based Varistor Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 310-313 ◽  
Author(s):  
Wang Chen Long ◽  
Jun Hu ◽  
Jin Liang He ◽  
Jun Liu ◽  
Feng Chao Luo
Keyword(s):  
Grain Boundary ◽  
Crystal Lattice ◽  
Saturation Effect ◽  
Type Curve ◽  
Non Linear ◽  
Zno Varistors ◽  
Al Addition ◽  
Zno Crystal ◽  
Zno Ceramics

The additive of Al(NO3)3 was doped into ZnO varistors in order to reduce their residual voltages. Some of doped Al3+ enter the ZnO grains and infill into the vacancies of Zn2+ ions in the crystal lattice. Then, the resistances of ZnO grains decrease, which finally results in lower residual voltages of varistor samples. However, when most of Zn2+ vacancies inside the ZnO crystal lattice are filled with Al3+, redundant Al3+ ions inside ZnO grains will increase the grains’ resistances contrarily. In this paper, ZnO and Al(NO3)3 binary ceramics sintered at 1300 °C for 2, 4 and 8 hours were studied. The J-E curves of the investigated samples exhibit weak non-linear characteristics which may be due to the formation of grain boundary. Moreover, The resistivity dependence of ZnO ceramics on Al addition behaves as a U-type curve and the lowest resistivity of ZnO ceramics is obtained with doping 0.25mol% Al3+.

scholarly journals Effect of light elements impurity atoms on grain boundary diffusion in FCC metals: a molecular dynamics simulation

2020 ◽  
Vol 62 (12) ◽  
pp. 930-935
Author(s):  
G. M. Poletaev ◽  
I. V. Zorya ◽  
R. Yu. Rakitin ◽  
M. D. Starostenkov
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Crystal Lattice ◽  
Grain Boundaries ◽  
Free Volume ◽  
Misorientation Angle ◽  
Light Elements ◽  
Self Diffusion ◽  
Impurity Atoms ◽  
Metal Atoms

Effect of carbon and oxygen impurity atoms on diffusion along the tilt grain boundaries with <100> and <111> misorientation axis in metals with FCC lattice was studied by mean of molecular dynamics method. Ni, Ag, and Al were considered as metals. Interactions of metal atoms with each other were described by many-particle Clery-Rosato potentials constructed within the framework of tight binding model. To describe interactions of atoms of light elements impurities with metal atoms and atoms of impurities with each other, Morse pair potentials were used. According to obtained results, impurities in most cases lead to an increase in self-diffusion coefficient along the grain boundaries, which is caused by deformation of crystal lattice near the impurity atoms. Therefore, additional distortions and free volume are formed along the boundaries. It is more expressed for carbon impurities. Moreover, with an increase in concentration of carbon in the metal, an increase in coefficient of grain-boundary self-diffusion was observed first, and then a decrease followed. This behavior is explained by formation of aggregates of carbon atoms at grain boundary, which leads to partial blocking of the boundary. Oxygen atoms had smaller effect on diffusion along the grain boundaries, which is apparently explained by absence of a tendency to form aggregates and lesser deformation of crystal lattice around impurity. The greatest effect of impurities on self-diffusion along the grain boundaries among the examined metals was observed for nickel. Nickel has the smallest lattice parameter, impurity atoms deform its lattice around itself more than aluminum and silver, and therefore they create relatively more lattice distortions in it and additional free volume along the grain boundaries, which lead to an increase in diffusion permeability. Diffusion coefficients along the high-angle boundaries with misorientation angle of 30° turned out to be approximately two times higher than along low-angle boundaries with a misorientation angle of 7°. Diffusion along the <100> grain boundaries flowed more intensively than along the <111> boundaries.

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