Reliability and Reproducibility Achieved via Grain Boundary Engineering of High Performance Electronic Ceramics.

1996 ◽  
Author(s):  
Vasantha R. Amarkoon ◽  
Brian C. LaCourse
Author(s):  
Shuankui Li ◽  
Zhongyuan Huang ◽  
Rui Wang ◽  
Chaoqi Wang ◽  
Wenguang Zhao ◽  
...  

The strong interrelation between electrical and thermo parameters have been regarded as one of the biggest bottlenecks to obtain high-performance thermoelectric materials. Therefore, to explore a general strategy to fully...


2012 ◽  
Vol 706-709 ◽  
pp. 2880-2885 ◽  
Author(s):  
Shigeaki Kobayashi ◽  
Ryouta Fukasawa ◽  
Tadao Watanabe

The evolution of grain boundary microstructures in gold thin films during annealing was investigated in order to find a clue to the development of high performance thin films by grain boundary engineering. The {111} oriented grains with the lowest surface energy were preferentially grown by surface energy-driven grain growth during annealing. The sharp {111} texture was developed by annealing at the temperature more than 873K. The remarkably high fraction of low-Σ coincidence site lattice (CSL) boundaries occurred when the area fraction of {111} texture increased to more than 95%. In particular, the fraction of some low-Σ CSL boundaries (Σ1,Σ3,Σ7) for the most sharply {111} textured specimen was found to be one order higher than those predicted for a random polycrystal. The utility of grain boundary engineering is discussed for controlling the performance degradation caused by the percolation phenomena of grain boundary diffusion in gold thin films.


2007 ◽  
Vol 558-559 ◽  
pp. 843-850 ◽  
Author(s):  
Tadao Watanabe ◽  
Kota Kido ◽  
Sadahiro Tsurekawa ◽  
Koichi Kawahara

A new approach to grain boundary engineering for photovoltaic polysilicon has been attempted using a new processing method of unidirectional and rotational solidification from the melt, in order to control the grain boundary microstructure and to produce desirable bulk electrical properties. The effect of grain boundary microstructure on bulk electrical properties of polysilicon can be more precisely evaluated by introducing a new parameter “directional grain boundary density (DGBD)” in connection with basic knowledge of structure-dependent grain boundary electrical properties, the grain boundary character distribution (GBCD) and grain boundary geometrical configuration which can be experimentally determined by Orientation Imaging Microscopy (OIM). We report the usefulness of this approach to development of high performance polysilicon.


Nano Energy ◽  
2017 ◽  
Vol 41 ◽  
pp. 501-510 ◽  
Author(s):  
Qihao Zhang ◽  
Zhenxing Zhou ◽  
Maxwell Dylla ◽  
Matthias T. Agne ◽  
Yanzhong Pei ◽  
...  

2011 ◽  
Vol 702-703 ◽  
pp. 703-709
Author(s):  
Tadao Watanabe ◽  
Shigeaki Kobayashi ◽  
Xiang Zhao ◽  
Liang Zuo

Bulk properties of polycrystalline structural and functional materials are controlled by the grain boundary microstructure defined by the grain boundary character distribution (GBCD) and grain boundary connectivity, because of percolation-dependent grain boundary phenomena. It has been found that there is a close relationship between microscale texture and grain boundary microstructure. Since percolation-controlled grain boundary phenomena are involved and playing key roles in the generation of various kinds of bulk properties, the relationship between texture and grain boundary microstructure can be effectively used as a powerful tool in development of high performance structural and functional materials by Grain Boundary Engineering (GBE).


2016 ◽  
Vol 7 ◽  
pp. 1829-1849 ◽  
Author(s):  
Shigeaki Kobayashi ◽  
Sadahiro Tsurekawa ◽  
Tadao Watanabe

A new approach to grain boundary engineering (GBE) for high performance nanocrystalline materials, especially those produced by electrodeposition and sputtering, is discussed on the basis of some important findings from recently available results on GBE for nanocrystalline materials. In order to optimize their utility, the beneficial effects of grain boundary microstructures have been seriously considered according to the almost established approach to GBE. This approach has been increasingly recognized for the development of high performance nanocrystalline materials with an extremely high density of grain boundaries and triple junctions. The effectiveness of precisely controlled grain boundary microstructures (quantitatively characterized by the grain boundary character distribution (GBCD) and grain boundary connectivity associated with triple junctions) has been revealed for recent achievements in the enhancement of grain boundary strengthening, hardness, and the control of segregation-induced intergranular brittleness and intergranular fatigue fracture in electrodeposited nickel and nickel alloys with initial submicrometer-grained structure. A new approach to GBE based on fractal analysis of grain boundary connectivity is proposed to produce high performance nanocrystalline or submicrometer-grained materials with desirable mechanical properties such as enhanced fracture resistance. Finally, the potential power of GBE is demonstrated for high performance functional materials like gold thin films through precise control of electrical resistance based on the fractal analysis of the grain boundary microstructure.


2017 ◽  
Vol 3 (4) ◽  
pp. 273-279 ◽  
Author(s):  
Han Li ◽  
Xianli Su ◽  
Xinfeng Tang ◽  
Qingjie Zhang ◽  
Ctirad Uher ◽  
...  

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