Electrical and FTIR studies on Al substituted Mn–Zn mixed ferrites

Abstract

Mixed ferrites of manganese and zinc with the substitution of aluminum are prepared by the ceramic double-sintering method. Confirmation of single-phase and polycrystalline ferrites is made from X-ray diffraction patterns and experimental and theoretical values of lattice constant are compared. Distribution of cations on A and B sites is concluded. A.c. conductivity and FTIR characterizations are done and the logarithm of conductivity (log σ) dielectric constant (ε) and tan δ at various frequencies (ω) and temperatures (T) are reported. Hopping of electrons between localized d bands of ions is the interesting feature of these ferrites and the mechanism of hopping is discussed. Activation energy and vibration frequencies are discussed as a function of aluminum concentration.