Effect of manganese substitution of ferrite nanoparticles on particle grain structure
Zichun Yan, Anish Chaluvadi, Sara FitzGerald, Sarah Spence, Christopher Bleyer, Jiazhou Zhu, Thomas Crawford, Rachel B. Getman, John Watt, Dale L. Huber, O. Thompson Mefford
Abstract
vibrating sample magnetometry. A discrepancy was found; the computational data demonstrated a positive correlation between manganese content and saturation magnetization, while the experimental data exhibited an inverse correlation. X-ray diffraction (XRD) and magnetometry results indicated that the crystallite diameter and the magnetic diameter decrease when adding more manganese, which could explain the loss of magnetization of the particles. For 20 nm nanoparticles, with increasing manganese substitution level, the crystallite size decreases from 10.9 nm to 6.3 nm and the magnetic diameter decreases from 15.1 nm to 3.5 nm. Further high resolution transmission electron microscopy (HRTEM) analysis confirmed the manganese substitution induced defects in the crystal lattice, which encourages us to find ways of eliminating crystalline defects to make more reliable ferrite nanoparticles.