Biphasic 0.8BaTiO₃/0.2Ni_(1-x)Co_xFe₂O₄ nanopowders by in situ sol-gel synthesis

Abstract

Nanopowders of the 0.8BaTiO₃/0.2Ni_(1-x)Co_xFe₂O₄ (x=0, 0.25, 0.5, 0.75, and 1) were synthesized by the in situ sol-gel method using poly(acrylic acid) (PAA1800) as a chelating agent. The synthesis developed using PAA1800 ensured the simultaneous crystallization of two phases. The results provided a reliable method for producing biphasic nanopowders in all the compositions of Co-Ni-ferrite with an average particle size of less than 50 nm with a potential application in lead-free magnetoelectric particulate composites. The XRD results indicated the formation of only BaTiO₃ and Ni_(1-x)Co_xFe₂O₄ phases, verifying that there was no interdiffusion between the perovskite BaTiO₃ and spinel Co-NiFe₂O₄ phases during the crystallization phase. A detailed analysis of the crystalline structures was conducted to quantify the phases using the Rietveld method, and thus ensure the success of the in situ sol-gel synthesis.

Keywords:
in situ sol-gel; 0.8BaTiO₃/0.2Ni_(1-x)Co_xFe₂O₄; nanopowders; biphasic system