Correlations of crystal structure, bond energy and microwave dielectric properties of AZrNb2O8 (A = Zn, Co, Mg, Mn) ceramics

The monoclinical structure AZrNb(2)O(8) (A = Zn, Co, Mg, Mn) ceramics were prepared by the conventional solid-state method. The microwave dielectric properties of AZrNb(2)O(8) (A = Zn, Co, Mg, Mn) ceramics exhibited significant dependence on the sintering conditions, microstructure and compositions. The crystalline structure refinement, chemical bond ionicity, lattice energy were carried out to investigate the correlations between the crystalline structure and microwave dielectric properties for AZrNb(2)O(8) (A = Zn, Co, Mg, Mn) ceramics based on the complex bond theory. The effects of A-site cations (Mn, Zn, Mg and Co) at AZrNb(2)O(8) compounds on structural parameters such as packing fraction and B-site octahedral distortion were studied based on Rietveld refinement. Variations in the dielectric constant (epsilon(r)) were explained by the ionic polarizability of the compositions. The quality factor (Q.f) and temperature coefficient of resonant frequency (tau(f)) were correlated with the packing fraction and B-site octahedral distortions (delta) in these compositions, respectively. Correlations between the microwave dielectric properties and crystal structure, the chemical bond energy were also discussed based on the variation of A-site ions. (C) 2015 Elsevier B.V. All rights reserved.