Study of (1-x)ZnAl2O4-xSiO2 spinel structures as microwave dielectric materials

摘要

Sol-gel method was used to synthesize zinc aluminate (ZnAl2O4) dispersed into silica matrix with different compositions of x. Morphological structure of (1—x)ZnAl2O4-xSiO2 samples were investigated by field emission scanning electron microscope (FESEM) and X-ray diffractometer (XRD). The FESEM images showed spherical structures and agglomerated particles occurred inside the samples. XRD analysis indicated the cubic phase formation of the samples. The crystallite size, D was calculated and it was found that the crystallite size are slightly increased from 8 to 17 nm. FTIR spectra analysis shows that the water presence in the samples and also the presence of nitrate group. The dielectric properties have been measured, ε_r value was found to be around 13.0. The S_(11) parameter analysis shows the samples was resonated at 2.40 GHz and gives different values of bandwidth for mi-crostrip patch antenna application.