High Dielectric Constant and Low-Loss Microwave Dielectric Ceramics Using (Zn0.95M2+0.05)Ta2O6 (M2+=Mn, Mg, and Ni) Solid Solutions

High dielectric constant and low-loss ceramics in the (Zn(0.95)M2+(0.05))Ta2O6 (M2+=Mn, Mg, and Ni) ceramic family have been prepared by the conventional mixed-oxide route and their crystal structures and microwave dielectric properties have been investigated. The forming of (Zn(0.95)M2+(0.05))Ta2O6 (M2+=Mn, Mg, and Ni) solid solutions was confirmed by the X-ray diffraction patterns, high-resolution transmission electron microscopic lattice images, the energy-dispersive X-ray analysis, and the measured lattice parameters. The dielectric properties exhibited a significant dependence on the sintering condition and crystal structure of the ceramics. A fine combination of microwave dielectric properties can be achieved in the (Zn0.95Mn0.05)Ta2O6 ceramics sintered at 1325 degrees C for 2 h with a dielectric constant of similar to 38.56, a Q x f value of similar to 92 700 GHz (where f=7.64 GHz, is the resonant frequency), and a temperature coefficient of resonant frequency (tau(f)) of similar to 8.9 ppm/degrees C. It is proposed as a suitable candidate material for small-sized global positioning system patch antennas.