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The aim of the present study was to prepare nanocomposites with different CoCr2O4 content (20%, 50%, and 80% CoCr2O4/SiO2 mass%) starting from Co(II) carboxylate and ammonium dichromate using a modified sol–gel method and to evaluate the final product (nature, size and shape) based on the different precursor amount. Thermal analysis was used in order to reveal the formation and decomposition of Co(II) carboxylate to CoO and (NH4)2Cr2O7 to Cr2O3+x, inside the silica gel pores. The oxide mixture interacts at temperatures of ~ 400 °C when Cr2O3+x turn to α-Cr2O3 which leads together with CoO to the formation of CoCr2O4 inside the SiO2 matrix. XRD and FTIR analyses revealed the formation of the single spinel structure in all synthesized samples. The results show that a higher cobalt chromite content inside the silica matrix leads to higher crystallinity. The particle sizes were in nanometer range, and the size variation was small from a sample to another, independent on the concentration (3.9–12.4 nm). [ABSTRACT FROM AUTHOR]