Investigations on structural, electrical and dielectric properties of yttrium substituted Mg-ferrites

Polycrystalline ferrites with chemical formula MgY2xFe2−2xO4 (x=0.0 to 0.12) have been fabricated by a double sintering ceramic technique. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Impedance spectroscopy and Fourier transform infrared (FTIR) spectroscopy. A slight increase in lattice constant is observed for x=0.02 and thereafter it decreased for higher Y-contents. The increase in lattice constant is attributed to the difference in ionic radii of the cations involved and decrease led to the formation of secondary phase (YFeO3). The substitution of yttrium impedes the grain growth. The resistivity at 298 K was significantly enhanced as the Y3+ was increased. The FTIR band positions in the range of 370-1100 cm−1 exhibited two main absorption bands. These bands confirmed the completion of solid state reaction. As the Yttrium contents were increased the dielectric parameters were greatly influenced. Both the observed/optimized electrical and dielectric parameters suggested the potential use of the Y-doped MgFe2O4 ferrites in high frequency devices fabrication.