[P2] RE-free Magnets

[P2-67] Synthesis of Re/Upcycled Sr-Ferrite Permanent Magnets from Mill Scale

*Duru Kalkavan¹, Nilay Gunduz Akdogan^1,3, Doruk Celebi^1,2, Ozan Akdogan^1,2 (1. NANOTerial Technology Corporation (Turkey), 2. Faculty of Engineering and Natural Sciences, Bahcesehir University (Turkey), 3. Faculty of Engineering, Piri Reis University (Turkey))

Keywords:

Ferrite magnet

This study used mill scale, an industrial waste, as an iron source to produce a Sr-Ferrite permanent magnet. Strontium is a critical raw material in high demand for permanent magnet applications, and its use through recycling is vital for sustainability. This study aims to enhance the magnetic properties of produced strontium hexaferrite (SrFe₁₂O₁₉) by doping various oxides. Al₂O₃, Cr₂O₃, Co₃O₄, and La₂O₃ were added to the structure by utilizing the mechanochemical approach to improve the magnetic properties. The doped oxides are expected to directly influence particle morphology and magnetic anisotropy. X-ray diffraction (XRD) analysis confirmed the suitability of the mill scale as an iron source and the successful formation of the SrFe₁₂O₁₉ phase after doping. In addition, it was determined by Scanning electron microscopy (SEM) analysis that all of the powders were below 10 microns and homogeneous. Thermogravimetric analysis (TGA) showed increased Curie temperature of the doped strontium hexaferrite. Vibrating sample magnetometry (VSM) analysis demonstrated a significant increase in remanent magnetization, coercivity, and magnetic anisotropy, aligning with the intended effects of oxide doping.