Dielectric properties of MgB₂O₆ (B⁵⁺=Nb, Ta, Sb) at microwave frequencies

Abstract

Microwave dielectric properties of MgB₂O₆ (B⁵⁺ = Nb, Ta, Sb) and their solid solutions have been investigated to control the temperature coefficient of resonant frequency (TCF) of MgTa₂O₆ ceramics. At the composition range of single phase, TCF of the sintered specimens was depended on the distortion of oxygen octahedra by the substitution of Nb and/or Sb for Ta of MgTa₂O₆. For the Mg(Ta_1-xNb_x)₂O₆ (0.2 ≤ x ≤ 0.8) and Mg(Ta_1-xSb_x)₂O₆ (0.1 ≤ x ≤ 0.4) sintered specimens, the quality factor (Qf) was decreased with x content. The dielectric constant (K) of the sintered specimens was dependent on the dielectric polarizabilities.