MICROWAVE DIELECTRIC-PROPERTIES AND STRUCTURE OF THE BA6-3XSM8-SOLUTIONS(2XTI18O54 SOLID)

The microwave dielectric properties of the Ba6-3xSm8+2xTi18O54 (0.3 le ss than or equal to x less than or equal to 0.7) solid solutions are s tudied in relation to the crystal structure. Q . f of suitable materia ls obtained by optimizing the sintering condition is in inverse propor tion to the dielectric constant (epsilon(r)). With increase of x, epsi lon(r) decreased and and Q . f increased. Good-quality microwave reson ators with epsilon(r)=80 and Q . f=9720 GHz can be obtained in the com position range of x=0.5 to 0.7 in the solid-solution region. Substitut ion of 2Sm(3+) for 3Ba(2+) in the large cation sites results in the cr eation of vacancies and crystal distortion, showing that the shrinkage of the TiO6 octahedral site plays an important role for improvement o f the microwave dielectric properties.