Magnetic properties of (Zn,Cd,Cu)-Co-Fe-Ti spinel oxides

AC susceptibility, magnetization and Mossbauer spectra have been measured f or (Zn, Cd, Cu)(0.5)Co0.9Fe1.2Ti0.4O4 and Zn0.3Co0.9Fe1.4Ti0.4O4 spinel oxi des. The variation of coercive field below the spin glass transition temper ature T-sg is found to fit a double exponential function of the form H-C(T) = H(1)e(-beta 1T) + H(2)e(-beta 2T), where H-i and beta(i) are constants. Mossbauer spectra and analysis show superparamagnetic fluctuations associat ed with magnetic clusters. Symmetric doublets above T-sg are decomposed int o quadrupole doublets associated with tetrahedral (A) and octahedral (B) si tes.