Investigation and characterization on crystal structure of ixiolite structure ATiNb2O8 (A = Mg, Zn) ceramics at microwave frequency based on the complex chemical bond theory

Ixiolite structure ATiNb(2)O(8) (A = Mg, Zn) microwave dielectric materials were prepared via the conventional solid state reaction method. The crystal structure was researched by X-ray diffraction. Rietveld refinement was used to analyze the crystal structure and the lattice parameters were obtained. Based on the complex chemical bond theory and lattice parameters, intrinsic factors such as the bond ionicity, lattice energy, bond energy and coefficient of thermal expansion were calculated. The relationships between structures and properties of ATiNb(2)O(8) (A = Mg, Zn) ceramics were researched. The microwave properties were strongly dependent on intrinsic factors. The dielectric constant (epsilon(r)) was strongly dependent on the bond ionicity of Nb-O bonds. The quality factor (Q.f) was mainly affected by the lattice energy of Nb-O bonds. The temperature coefficient of resonant frequency (tau(f)) could be mainly influenced by the bond energy and coefficient of the thermal expansion of Nb-O bonds. (C) 2016 Elsevier B.V. All rights reserved.