The effect of Ce3+ and La3+ ions on ferromagnetism ferroelectricity and dielectric coexistence of Pb0 7Sr0 3[(Fe2/3Ce1/3)(0 012)Ti-0 988]O-3 (PSFCT) and Pb0 7Sr0 3[(Fe2/3La1/3)(0 012)Ti-0 988]O-3 (PSFLT) nanoparticles has been studied Rietveld analysis of X-ray diffraction has been used to find the structural parameters The average particles size is measured by using transmission electron microscopy Ce3+ and La3+ ions create one more lone pair of electrons with Pb2+ is responsible for large polarization and the ferromagnetism is related with the number of free electrons in 4f and 3d orbitals The temperature dependent relative permittivity shows diffuse phase transition (DPT) has been calculated from modified Curie-Weiss law and relaxor characteristics by Vogel-Fulcher relation The temperature dependent dc resistivity shows that the PSFCT and PSFLT nanoparticles involve variable range hopping conduction mechanism The Cole-Cole model has been used to find the effect of interfaces grain and grain boundaries on the electrical properties (C) 2010 Elsevier B V All rights reserved