Microwave dielectric properties of tungstenbronze type like (Ba1-αSrα)6-3xR8+2xTi18O54 (R = Sm, Nd) solid solutions

Tungstenbronze type like Ba6-3xR8+2Ti18O54 (R = Sm or Nd) dielectric ceramics reveal high quality factor Q center dot f as well as high dielectric constant epsilon(r). We have investigated the effect of Sr substitution for Ba ions on the microwave dielectric properties of the compounds. (Ba1-alpha Sr alpha)(6-3x)R8+2xTi18O54 (R = Sm or Nd) ceramics were prepared in the composition ranges of x = 0-0.2 and alpha = 0-0.312 and the microwave dielectric properties were investigated. (Ba1-alpha Sr alpha)(6-3x)Sm8+2xTi18O54, where x = 0.1 and alpha = 0.298, and (Ba1-alpha Sr alpha)(6-3x)Nd8+2xTi18O54, where x = 0.2, alpha = 0.296 revealed remarkably higher Q center dot f value among the solid solutions, indicating that Q center dot f increased with substituting Sr ions into Ba ions at the rhombic A1-site. This fact suggests that relaxation of local distortions at the A1-sites is closely related to improvement of Q center dot f (C) 2007 Elsevier Ltd. All rights reserved.