Epitaxial thin films

Abstract

Epitaxial thin films for use as buffer layers for high temperature superconductors, electrolytes in solid oxide fuel cells (SOFC), gas separation membranes or dielectric material in electronic devices, are disclosed. By using CCVD, CACVD or any other suitable deposition process, epitaxial films having pore-free, ideal grain boundaries, and dense structure can be formed. Several different types of materials are disclosed for use as buffer layers in high temperature superconductors. In addition, the use of epitaxial thin films for electrolytes and electrode formation in SOFCs results in densification for pore-free and ideal grain boundary/interface microstructure, Gas separation membranes for the production of oxygen and hydrogen are also disclosed. These semipermeable membranes are formed of high-quality, dense, gas-tight, pinhole free sub-micron scale layers of mixed-conducting oxides on porous ceramic substrates. Epitaxial thin films as dielectric material in capacitors are also taught herein. Capacitors are utilized according to their capacitance values which are dependent on their physical structure and dielectric permittivity. The epitaxial thin films of the current invention form low-loss dielectric layers with extremely high permittivity. This high permittivity allows for the formation of capacitors that can have their capacitance adjusted by applying a DC bias between their electrodes.

1 . An electrolyte for an SOFC, said electrolyte comprising an epitaxial thin film.  
     
     
         2 . The electrolyte of  claim 1  wherein said epitaxial thin film comprises substantially a single crystal.  
     
     
         3 . The electrolyte of clam  1 , having an electrode directly deposited on a surface of the electrolyte.  
     
     
         4 . An SOFC, comprising: 
 an anode layer;    a layer of the electrolyte according to  claim 1  on said anode layer; and    a cathode layer on said electrolyte layer.    
     
     
         5 . The SOFC of  claim 4  wherein said epitaxial thin film comprises a single crystal.