Bipolar Cascade Emitters for Radio-Frequency and Electro-Optical Applications

2008 ◽  
Author(s):  
William J. Siskaninetz ◽  
Reginald J. Turner
Author(s):  
J. R. Heffelfinger ◽  
C. B. Carter

Transmission-electron microscopy (TEM), scanning-electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) were used to investigate the solid-state reaction between a thin yttria film and a (0001) α-alumina substrate. Systems containing Y2O3 (yttria) and Al2O3 (alumina) are seen in many technologically relevant applications. For example, yttria is being explored as a coating material for alumina fibers for metal-ceramic composites. The coating serves as a diffusion barrier and protects the alumina fiber from reacting with the metal matrix. With sufficient time and temperature, yttria in contact with alumina will react to form one or a combination of phases shown by the phase diagram in Figure l. Of the reaction phases, yttrium aluminum garnet (YAG) is used as a material for lasers and other optical applications. In a different application, YAG is formed as a secondary phase in the sintering of AIN. Yttria is added to AIN as a sintering aid and acts as an oxygen getter by reacting with the alumina in AIN to form YAG.


2006 ◽  
Vol 175 (4S) ◽  
pp. 16-16 ◽  
Author(s):  
Joshua M. Stern ◽  
Robert S. Svatek ◽  
Sangtae Park ◽  
J. Kyle Anderson ◽  
Yair Lotan ◽  
...  

2004 ◽  
Vol 171 (4S) ◽  
pp. 505-505
Author(s):  
Edward D. Matsumoto ◽  
Lori Watumall ◽  
D. Brooke Johnson ◽  
Kenneth Ogan ◽  
Grant D. Taylor ◽  
...  

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