Study of neodymium addition on the magnetic and structural properties of strontium hexaferrite synthesized by the Pechini method

Abstract

This work reports a systematic study of the effect of neodymium (Nd) on the microstructural, magnetic, and structural properties of strontium hexaferrite (SrFe12O19). Neodymium was incorporated during the hexaferrite fabrication using the sol–gel Pechini method. The results show that neodymium is partially incorporated into the hexaferrite crystal structure, allowing the formation of neodymium orthoferrite as a second phase, which dramatically affects the magnetic properties of the hexaferrite. The temperature in the range of 900 to 1100 °C and the variation of the neodymium content were two analytical variables that allowed to study the effects of neodymium on the hexaferrite properties. The behavior of the phases and their structural properties were investigated using X-ray diffraction and the Rietveld refinement method. The magnetic properties were obtained using vibrant sample magnetometry, and the microstructural characteristics were analyzed by electron microscopy. For the hexaferrite containing up to 2.85 wt% of neodymium orthoferrite, the maximum energy product (BHmax) was 35% higher than the one showed by the neodymium-free hexaferrite. The increased magnetic properties have been associated with the incorporation of neodymium in the hexaferrite structure and due to the magnetic interactions between the hexaferrite and neodymium orthoferrite.