Engineering Desired Grain Orientation and Boundaries Separating Adjacent Grains in Polycrystalline Thin Films

1995 ◽  
Vol 403 ◽  
Author(s):  
I. A. Rauf ◽  
M. Sayer
Keyword(s):  
Temperature Gradient ◽  
Grain Boundaries ◽  
Grain Orientation ◽  
Coincidence Site Lattice ◽  
Low Energy ◽  
Zone Refining ◽  
Small Temperature ◽  
Polycrystalline Thin Films ◽  
Small Temperature Gradient ◽  
A Chain

AbstractA simple process, involving a controlled temperature gradient on the surface of the substrate during the deposition of a thin film is described. This technique is similar to zone-refining but produces chains of impurity free grains. Simultaneously, dopants and other defects are confined to the grain boundaries separating two such chains. For a small temperature gradient only preferred orientation is obtained within a chain. For medium values of temperature gradient the grain boundaries within a chain are engineered to be either on a low energy coincidence site lattice (CSL) or a twin depending on the magnitude of gradient. For high magnitudes of temperature gradient, the chain is predicted to be a single crystal strip.

A Role of Low Energy Grain Boundaries in the Abnormal Grain Growth in Fe-3%Si Alloy

2011 ◽  
Vol 127 ◽  
pp. 89-94 ◽  
Author(s):  
Ye Chao Zhu ◽  
Jiong Hui Mao ◽  
Fa Tang Tan ◽  
Xue Liang Qiao
Keyword(s):  
Grain Boundaries ◽  
Grain Growth ◽  
Electron Backscatter Diffraction ◽  
Dominant Role ◽  
Coincidence Site Lattice ◽  
Diffraction Method ◽  
Abnormal Grain Growth ◽  
Low Energy ◽  
Backscatter Diffraction

Low energy grain boundaries were considered to be important in abnormal grain growth by theoretical deduction. The disorientation angles and coincidence site lattice grain boundaries distribution of more than 20 Goss grains and their neighboring matrix grains in primary recrystallized Fe-3%Si alloy were investigated using an electron backscatter diffraction method. It was found that the frequency of low energy grain boundaries of Goss grains which are more likely to abnormally grow are higher than their neighboring matrix grains, which indicated that low energy grain boundaries play a dominant role in the abnormal grain growth of Fe-3%Si alloy. The result meets well with the abnormal grain growth theory.

Toward Realizing the Structure-Property Link in Polycrystalline Thin Films

1994 ◽  
Vol 343 ◽  
Author(s):  
C. S. Nichols
Keyword(s):  
Thin Films ◽  
Grain Boundaries ◽  
Coincidence Site Lattice ◽  
Polycrystalline Materials ◽  
Structure Property ◽  
New Approach ◽  
Site Lattice ◽  
Polycrystalline Thin Films ◽  
Structures And Properties ◽  
Polycrystalline Form

ABSTRACTMany materials for engineering applications are used in polycrystalline form and contain grain boundaries with a range of structures and properties. However, most research on grain boundaries to date has focussed exclusively on symmetric coincidence site lattice interfaces. To go beyond descriptions for these simple interfaces and thence to an aggregate of grains and grain boundaries in a polycrystal will require a new approach. Here we discuss two models for properties of polycrystalline materials, including their advantages and drawbacks, and indicate the microstructural variables available to optimize properties.

Grain boundary in textured YBa2Cu3O7−δ superconductor

1991 ◽  
Vol 6 (12) ◽  
pp. 2507-2518 ◽  
Author(s):  
Yimei Zhu ◽  
H. Zhang ◽  
H. Wang ◽  
M. Suenaga
Keyword(s):  
Grain Boundaries ◽  
Coincidence Site Lattice ◽  
Large Angle ◽  
Low Energy ◽  
Site Lattice ◽  
Microscopy Technique ◽  
Rotation Axes ◽  
Transmission Electron ◽  
Complex Crystal Structure ◽  
Complex Crystal

The misorientations of over 200 pairs of adjacent grains separated by grain boundaries in textured YBa2Cu3O7−δ were measured using a transmission electron microscopy technique. The results indicate that there exist discrete preferred rotation angles and rotation axes. The existence of low-energy boundaries is inferred. The results are analyzed based on the Constrained Coincidence Site Lattice (CCSL) and O2-lattice theories and imply the applicability of such theories for the case of large-angle grain boundaries in a complex crystal structure such as YBa2Cu3O7−δ. The results of analysis also show that some boundaries are likely to be reduced in oxygen near the boundary to satisfy the constraint of the coincidence site lattice.

EXPERIMENTAL INVESTIGATION ABOUT EDISON TYPE THERMOMAGNETIC MOTORS BEHAVIOR OPERATING WITH A SMALL TEMPERATURE GRADIENT

2021 ◽  
Author(s):  
Carlos Vinicius Xavier Bessa ◽  
João de Sá Brasil Lima ◽  
Bruno Chieregatti ◽  
Ricardo Galdino ◽  
Lucas Diego Rodrigues Ferreira
Keyword(s):  
Experimental Investigation ◽  
Temperature Gradient ◽  
Small Temperature ◽  
Small Temperature Gradient

On the Role of the Crystallographic Grain Characteristics in the Corrosion Behavior of Polycrystalline Copper

2014 ◽  
Vol 783-786 ◽  
pp. 1658-1663
Author(s):  
Linsey Lapeire ◽  
Esther Martinez Lombardia ◽  
Kim Verbeken ◽  
Iris de Graeve ◽  
Leo Kestens ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Grain Orientation ◽  
Electron Backscatter Diffraction ◽  
Chemical Interaction ◽  
Coincidence Site Lattice ◽  
Pure Copper ◽  
Copper Substrate ◽  
Decisive Role ◽  
Special Boundaries

In order to increase the sustainability of metals, a more detailed understanding of the corrosion phenomenon is of crucial importance. In current literature, corrosion is often considered as a purely chemical interaction with nearly exclusive dependence on compositional effects, whilst ignoring the microstructural features of the metal surface. In the present work, results are presented which illustrate both the role of grain orientation and grain boundaries in the corrosion process. To evaluate the grain orientation dependent electrochemical behavior, polycrystalline Cu, was brought into contact with a corrosive electrolyte. Subsequently, the attack was evaluated by measuring the surface with both Atomic Force Microscopy (AFM) and Electron Backscatter Diffraction (EBSD). It was demonstrated that the grain orientation itself did not significantly influence the corrosion kinetics, but, alternatively, that the orientation of the neighboring grains seemed to play a decisive role in the grain dissolution rate. To increase understanding on the role of grain boundaries, a method was developed based on the electrochemical (galvanic) displacement of gold, which is deposited from an aqueous solution on a pure copper substrate. This technique demonstrated its sensitivity to the grain boundary characteristics as far less gold was deposited on special boundaries, such as coincidence site lattice boundaries, as compared to the random high angle grain boundaries.

Energy Harvesting under Large Temperature Gradient – Comparison of Silicides, Half-Heusler Alloys and Ceramics

2015 ◽  
Vol 2 (1-2) ◽  
Author(s):  
Wilfried Wunderlich
Keyword(s):  
Energy Harvesting ◽  
Temperature Gradient ◽  
Seebeck Coefficient ◽  
Heusler Alloys ◽  
Large Temperature ◽  
Analysis Method ◽  
Small Temperature ◽  
Large Temperature Gradient ◽  
Small Temperature Gradient

AbstractThis paper reports about a new four-step analysis method for thermoelectric (TE) materials. While the Seebeck coefficient is usually measured under small temperature gradient, we report here the measurement of TE materials under large temperature gradient. The examined materials were Ag- and Bi-doped Mg

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