Bond analysis of novel MnZrTa 2 O 8 microwave dielectric ceramics with monoclinic structure

Abstract

A new type of ceramic, namely MnZrTa₂O₈, was synthesized after sintering at high temperature in this work. The possible dielectric loss mechanism was discussed by Raman spectroscopy and chemical bond theory. X-ray diffraction indicated that MnZrTa₂O₈ formed through a reaction between ZrO₂ and intermediate MnTa₂O₆. After sintering at 1350 °C, a monoclinic structure with cell parameters a = 4.8370(3) Å, b = 5.7163(1) Å, c = 5.1398(5) Å, β = 91.7219° was gained for ceramic. Among all bonds, Ta–O with the greatest bond ionicity and lattice energy was the dominant factor that influenced the microwave dielectric properties. The temperature coefficient of the resonant frequency τ_f changed from − 50.55 to − 41.21 ppm/ °C, which was related to the lattice energy. The effect of porosity on dielectric loss was also checked and found to be significant. MnZrTa₂O₈ ceramic exhibited relative permittivity ε_r ~ 23.0 and enhanced quality factor Q × f~48103 GHz (at 8.97 GHz), which provided a promising candidate for electric components.