Physical properties of substituted M0.5Fe2.5O4 ferrite spinels with M= (Mn and Zn)

Two ferrite ceramic materials, Mn0.5Fe2.5O4 and Zn0.5Fe2.5O4 were produced by the autocombustion method. X-ray diffraction (XRD) analysis indicates the formation of a spinel phase with a cubic structure. FTIR spectra are used to study the elastic properties which leads to a ductile nature of our compounds. The UV-Visible absorption results indicate that the gap energy of these compounds is 3.21 and 3.16 eV for Mn0.5Fe2.5O4 and Zn0.5Fe2.5O4 respectively. The conduction process is dominated only by the NSPT model for Mn0.5Fe2.5O4 while for Zn0.5Fe2.5O4 by CBH and NSPT. The scaling law shows an overlay of curves of impedance and modulus respectively reflecting the temperature independence of the relaxation process. Nyquist diagrams show incomplete semicircle arcs whose fitting leads to an equivalent electrical circuit reflecting the contribution of the grains. The low conductivity, high permittivity and low dielectric losses at room temperature and low frequency make these compounds extremely interesting for the fabrication of electrical and microwave devices.