Tapioca starch in the sol-gel synthesis of cobalt ferrites with divalent cation substitutions

Abstract

An aqueous solution of tapioca starch was successfully used as a chelating agent in the solegel synthesis ofCo0.7Me0.3Fe2O4, where Me denotes Co, Mn, Cu, Ni, or Zn. The hysteresis loops of all sintered ferrites revealed ferrimagnetic properties. The saturation magnetization was reduced in Co0.7Cu0.3Fe2O4 and Co0.7Ni0.3Fe2O4 because of theion substitutions with smaller magnetic moments. Interestingly, Co0.7Cu0.3Fe2O4 exhibited the highest saturationmagnetization and the lowest coercive field. This result demonstrates the value addition of local agricultural products incontrolling nanoparticle formation during solegel synthesis.