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 epsilon = 120 and up to 3000 for epsilon = 80 at f = 4 GHz, have been developed based on BLT solid solutions. (C) 1999 American Institute of Physics. [S1063-7834(99)03205-0].