The Ni0.25Mn0.75Fe2O4 nanoparticles have been synthesized employing sol-gel combustion technique using metal nitrates of Ni, Mn and Fe with citric acid as a source. Polyvinyl alcohol has been added as a capping agent. The prepared samples were calcined at different temperatures namely 500 °C, 700 °C and 900 °C, respectively for 1 h. The particles were characterized by its structural (XRD, FTIR), morphological (AFM) and magnetic (Mössbauer) studies. The size of the prepared particle size is in range of 25-100 nm. The particle size and structure of the ferrite materials have been confirmed by XRD. The FTIR study confirms the presence of functional groups. Additionally, DTA-TG and Mössbauer studies have been made to explore the thermal and magnetic properties of the prepared samples. The above studies reveal that the sol-gel combustion technique can be used to different applications particularly for storage device applications. © 2008 Elsevier B.V. All rights reserved.