Investigation of crystal structure, microstructure and low temperature magnetic behavior of Ce⁴⁺ and Zn²⁺ co-doped barium hexaferrites (BaFe₁₂O₁₉)

Abstract

Ce⁴⁺ and Zn²⁺ co-doped barium hexaferrites (BFO) have been synthesized <i>via</i> a citrate-nitrate autocombustion route. Phase purity has been confirmed by high resolution (HR) powder X-ray diffraction analysis. Rietveld refinement on HR-XRD data has been carried out to reveal the crystal structure, bond angles and bond lengths. High-resolution scanning electron microscope (HR-SEM) has been used to study the effect of Ce⁴⁺ and Zn²⁺ on microstructure. Magnetic behavior of co-doped barium hexaferrites in the low temperature regime, 2-300 K has been studied. Further, it has been explained on the basis of superexchange interactions and formation of Bloch walls due to the presence of imperfections in the doped samples. It has been found that BFO changes hard to soft magnetic behavior when the temperature is decreased from 300 K to 2 K. Moreover, doping of Ce⁴⁺ and Zn²⁺ at Fe³⁺ site also brings similar effects which strengthens with decreasing temperature.