The ferrite system Co0.6Zn0.4CuxFe2-xO4 less than or equal to x less than or equal to 1, is studied by Mossbauer spectroscopy at room temperature, infrared spectra, and mobility measurements. The Mossbauer studies show that the samples are ferrimagnetic for all values of x; the hyperfine parameters of the tetrahedral and octahedral sites are determined as functions of x and so the cation distributions and spontaneous magnetization are deduced. Four bands are observed in the IR spectra. The high-frequency band v(1) is assigned to the tetrahedral cations and the low-frequency band v(2) to the octahedral complexes. The small band v(3) is assigned to the divalent octahedral metal ion. The lowest band v(4) is attributed to the lattice vibrations of the system. The drift mobility at different temperatures is determined for all compositions of our system and the activation energies are deduced.