USE OF SOLID STATE ELECTROCHEMICAL TRANSDUCER TECHNIQUES FOR CONTROL OF THE POINT DEFECT STRUCTURE IN SOLIDS.

Studies of the crystal structure and ionic transport in materials containing beta alumina and related phases are reported. Beta alumina has the nominal formula MAl11O17, where M is Li, Na, K, NH4, Ag, or Tl. The structure of the adjacent M2O-rich phase was studied and found to have an analogous structure consisting of dense blocks with the gamma alumina structure separated by low-density bridging layers containing M ions. Unusually rapid ionic transport along these bridging layers was found, and defect models appropriate to such systems discussed. (Author)