High dielectric constant microwave ceramics

The isomorphism regions and a behavior of the electric parameters in relation to the BaLn(2)Ti(4)O(12) (BLT) solid solution composition for the (A(x)Ba(1-x))(B(y)Ln(2-y))(CzTi4-z)O-12 system, where Ln=Nd, Sm and A stands for Sr or Pb, B stands for Bi; C stands for Zr are studied. The dielectric constant of solid solutions can lie in the range 80-125 with the temperature coefficient of dielectric constant near to zero. The advantage of the chemical precipitation technique over the solid-phase synthesis for obtaining of a ceramics with maximum epsilon and quality factor is shown. A study of the quality factor of materials on the base of the BLT solid solutions has shown rather weak temperature dependence within the range -80- + 80 C degrees. The dielectric constant of the obtained materials does not change up to the submillimeter band and the product of the quality factor and of the frequency is practically constant. (C) 2001 Elsevier Science Ltd. All rights reserved.