Crystal structure and microwave dielectric properties of (1−x)ZnTa2O6–xTiO2 ceramics

Characterization of TixZn(1-x)Al2O4 thin films by sol-gel method for GPS patch antennae

“…The observed diffraction peaks of ZnAl 2 O 4 doped with TiO 2 are consistent with these previously reported [10][11][12]. Furthermore, the peak positions of the phases shift slightly toward higher angles with increasing TiO 2 , which indicates that the cell volume of the spinel phase increases gradually due to the ionic radius of TiO 2+ (0.94 nm) [13] being larger than that of Zn 2+ (0.74 nm) [14] in the TiO 2 -doped ZnAl 2 O 4 compound. The XRD diffraction peaks shift to higher angle with increasing x value, which tends to decrease the lattice parameter (a).…”

“…Increasing the amount of TiO 2 loading was also found to result in a linear increase in the crystallite size from 20.92 (x = 0.10) to 31.63 nm (x = 0.30). The crystallite size increased due to the ionic radius of Ti 2+ (0.94 nm) [13] being larger than that of Zn 2+ (0.74 nm).…”

Synthesis and fabrication of GPS patch antennas by using Zn(1 − x)Ti x Al2O4 thin films

“…Furthermore, the peak positions of the phases shift slightly toward the higher angle with increasing x, which suggests a reduction in the unitcell dimension due to the improvement of crystallizability. The phenomenon of peak shifts has also been discussed in previous papers by Lei et al [7] and Park et al [14]. The XRD diffraction peaks shift to the higher degree, tend to decrease the lattice parameter (a) [15], and is able to increase the ceramic densities [14].…”

“…The calculated crystallite size of ZnAl 2 O 4 is 21.44 nm. As x increased, the crystallite size of the Zn (1 -x) Ti x Al 2 O 4 thin films increased from 21.44 to 39.63 nm due to a larger ionic radii of TiO 2 (0.94 nm) [14]. The increase in the crystallite size was in parallel with TiO 2 loading due to the requirement of high energies for the Ti 2?…”

“…It has been reported that the sol-gel method was a useful and attractive technique to prepare ZnAl 2 O 4 material. This sol-gel method offers the advantages of good stoichiometric control and high homogeneity, producing pure and ultrafine powders, and is able to produce thin films at low temperature processing (\900°C) [14,15].…”