scholarly journals A GRAIN-BOUNDARY CONDUCTION MODEL FOR STABILIZED-ZIRCONIA

1998 ◽  
Vol 47 (8) ◽  
pp. 1332
Author(s):  
GUOXIN
Keyword(s):  
Grain Boundary ◽  
Stabilized Zirconia ◽  
Conduction Model ◽  
Boundary Conduction

The influence of alumina addition and its distribution upon grain-boundary conduction in 15 mol.% calcia-stabilized zirconia

2001 ◽  
Vol 27 (3) ◽  
pp. 269-276 ◽  
Author(s):  
Jong-Heun Lee ◽  
Toshiyuki Mori ◽  
Ji-Guang Li ◽  
Takayasu Ikegami ◽  
Satoshi Takenouchi
Keyword(s):  
Grain Boundary ◽  
Stabilized Zirconia ◽  
Alumina Addition ◽  
Boundary Conduction

Precursor scavenging of the resistive grain-boundary phase in 8 mol% yttria-stabilized zirconia: Effect of trace concentrations of SiO2

2001 ◽  
Vol 16 (8) ◽  
pp. 2377-2383 ◽  
Author(s):  
Jong-Heun Lee ◽  
Toshiyuki Mori ◽  
Ji-Guang Li ◽  
Takayasu Ikegami ◽  
John Drennan ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Yttria Stabilized Zirconia ◽  
Impurity Level ◽  
Boundary Phase ◽  
Inhomogeneous Distribution ◽  
Stabilized Zirconia ◽  
Boundary Area ◽  
Average Grain Size ◽  
Trace Concentrations ◽  
Boundary Conduction

The influence that trace concentrations of SiO2have on improving grain-boundary conduction via precursor scavenging using additional heat treatment at 1200 °C for 40 h before sintering was investigated. At a SiO2-impurity level (SIL) ≤160 ppm by weight, the grain-boundary resistivity (ρgb) decreased to 20% of its value, while no improvement in grain-boundary conduction was found at a SIL ≥ 310 ppm. The correlation between the resistance per unit grain-boundary area, rgb, and average grain size indicated that the inhomogeneous distribution of the siliceous phase in the sample with a SIL ≥ 310 ppm hampered the scavenging reaction.

Effect of thermal annealing on grain boundary chemistry of polycrystalline TiBa2Ca2Cu3Oy films

1994 ◽  
Vol 52 ◽  
pp. 968-969
Author(s):  
Z. L. Wang ◽  
C. L. Briant ◽  
J. DeLuca ◽  
A. Goyal ◽  
D. M. Kroeger ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Weak Link ◽  
Zero Field ◽  
Stabilized Zirconia ◽  
Local Texture ◽  
Transmission Electron ◽  
Axis Alignment ◽  
Boundary Chemistry ◽  
Small Misorientation ◽  
Misorientation Angles

Recent studies have shown that spray-pyrolyzed films of the Tl-1223 compound (TlxBa2Ca2Cu3Oy, with 0.7 < × < 0.95) on polycrystalline yttrium stabilized zirconia substrates can be prepared which have critical current density Jc near 105 A/cm2 at 77 K, in zero field. The films are polycrystalline, have excellent c-axis alignment, and show little evidence of weak-link behavior. Transmission electron microscopy (TEM) studies have shown that most grain boundaries have small misorientation angles. It has been found that the films have a nigh degree of local texture indicative of colonies of similarly oriented grains. It is believed that inter-colony conduction is enhanced by a percolative network of small angle boundaries at colony interfaces. It has also been found that Jc is increased by a factor of 4 - 5 after the films were annealed at 600 °C in oxygen. This study is thus carried out to determine the effect on grain boundary chemistry of the heat treatment.

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