Microwave Dielectric Properties of the Ba_6-3x(Sm_1-y,\mbR_y)_8+2xTi₁₈O₅₄ (\mbR=Nd and La) Solid Solutions with Zero Temperature Coefficient of the Resonant Frequency

Abstract

Ba 6-3 x (Sm 1- y , R y ) 8+2 x Ti 18 O 54 ( R = Nd and La; x = 0.6, 0.0 ≤ y ≤1.0) solid solutions in which Nd or La ions are substituted for Sm ions were studied from the point of microwave dielectric materials. In both Sm-Nd and Sm-La series, formation of solid solutions was found, which was deduced from linear change of the lattice parameters. We found high-quality resonator materials in the both series which show high ε r of 84, Q · f products of 9000 GHz, and temperature coefficient of resonance frequency τ f =0 ppm/\CC. The compositions of those materials in the Sm-Nd and the Sm-La series were determined to be y = 0.2 and 0.1, respectively. A relationship between dielectric constant and volume of octahedron is also stated.