Bond ionicity,lattice energy,bond energy,and microwave dielectric properties of Ca1-xSrxWO4 ceramics

The Ca_1-xSr_xWO₄ (x?=?0, 0.02, 0.04, 0.06, 0.08, 0.10) ceramics were fabricated through solid-state reaction, and the relationships among microwave dielectric properties of Ca_1-xSr_xWO₄, bond ionicity, lattice energy and bond energy were systematically investigated for the first time. The patterns of X-ray diffractions of Ca_1-xSr_xWO₄ presented tetragonal scheelite structure and no second phase appeared throughout the entire compositions. Dielectric properties of Ca_1-xSr_xWO₄ were proved to be related to the microstructures: dielectric constant (ε_r) of Ca_1-xSr_xWO₄ was dependent on the bond ionicity; the quality factor (Q×f₀) of Ca_1-xSr_xWO₄ was affected by W-site lattice energy when intrinsic loss is dominant; the temperature coefficient of resonant frequency (|τ_f|) would increase if B-site bond energy decreased. Ca_1-xSr_xWO₄ ceramic showed excellent microwave dielectric properties, ε_r =?9.42, Q×f₀ =?79876?GHz and τ_f =??18.8?ppm/°C when x?=?0.08 and sintered at 1100?°C for 4?h.