Dielectric properties of polycrystalline Cu–Zn ferrites at microwave frequencies

The real dielectric constant ɛ′ and complex dielectric constant ɛ″ of Cu1−xZnxFe2O4 have been measured at room temperature in the high frequency range 1 MHz to 1.8 GHz. At low frequencies the dielectric loss is found to be constant up to 1.4 GHz and there is a sudden rise at 1.5 GHz. A qualitative explanation is given for the composition, frequency dependence of the dielectric constant and dielectric loss of Cu1−xZnx Fe2O4. These are correlated with the W–H plot which gives the information about change in the average crystal size and strain of the samples. The micro-morphological features of the samples were obtained by Scanning Electron Microscopy (SEM). The micrograph shows that the increase of the Zn content in Cu ferrite increases the grain size.

► Cu1−x ZnxFe2O4 at different concentration are suitable for high frequency applications.
► Dielectric properties are related with W-H plot.
► The anisotropy due to the crystallite size effect is significant in change of dielectric constant.