Effects of structural characteristics on microwave dielectric properties of low-loss (Zn1-xNix)ZrNbTaO8 ceramics

Low-loss (Zn1-xNix)ZrNbTaO8 (0.02 ≤ x ≤ 0.10) ceramics possessing single wolframite structure are initiatively synthesized by solid-state route. Based on the results of Rietveld refinement, complex chemical bond theory is used to establish the correlation between structural characteristics and microwave performance in this ceramic system. A small amount of Ni2+ (x = 0.06) in A-site with the fixed substitution of Ta5+ in B-site can effectually raise the Q × f value of ZnZrNb2O8 ceramic, embodying a dense microstructure and high lattice energy. The dielectric constant and τf are mainly affected by bond ionicity and the average octahedral distortion. The (Zn0.94Ni0.06)ZrNbTaO8 ceramic sample sintered at 1150 °C for 3 h exhibits an outstanding combination of microwave dielectric properties: εr = 27.88, Q × f = 128,951 GHz, τf = -39.9 ppm/°C. Thus, it is considered to be a candidate material for the communication device applications at high frequency.