Ceramic materials for use in microwave electronics

A study is reported of the structure and electrical properties of BaLn 2 Ti 4 O 12 compositions (BLT), where Ln=La, Nd, or Sm, with calcium, strontium, or lead substituted for barium, and bismuth for the lanthanide. The BLT compound is shown to be characterized by a broad isomorphicity region, at the edge of which form solid solutions with the highest dielectric permittivity reached thus far, up to about 170. A number of thermally stable ceramic materials with a high dielectric permittivity of 80 to 120, which permit construction of microwave dielectric resonators with Q factors of up to 600 for ɛ =120 and up to 3000 for ɛ =80 at f =4 GHz, have been developed based on BLT solid solutions.