Spinel ferrite nano-powders are highly useful in applications such as drug-delivery, ferrofluids, gas sensors, etc. because of their semiconductor and ferromagnetic properties. There are various methods by which the spinel ferrites can be synthesized, i.e., hydro-thermal route, solid-state route, sol-gel route, thermal deposition route, mechanical milling, etc. In this work, nano-crystalline Cu-Zn ferrites with the composition of (Cu0.4Zn0.6Fe2O4) were synthesized from metal nitrate and acetate precursors by the hydro-thermal route and sol-gel auto-combustion route. Citric acid was used as a fuel to increase the rate of reaction. Synthesized powders were heat-treated for different holding time. The crystal structures of these compounds were characterized by X-ray diffraction (XRD). The crystal size and lattice parameter were determined by using Maud analysis and Williamson-hall plots. The Rietveld analysis and X'Pert Highscore peak match analysis confirmed the formation of single-phase Cu0.4Zn0.6Fe2O4. It was observed that crystallite size and peak intensity increased after heat treatment. Also, on increasing the holding time of heat treatment, an increase in the peak intensity and crystallite size was observed.