Defects and dopant alliance towards bound magnetic polarons formation and mixed magnetic characteristics in Fe doped ZnO nanoparticles

摘要

Fe doped ZnO powders, Zn1-xFexO (x = 0-0.03) confirmed to be single phased using X-ray diffraction (XRD) measurement (step size of 0.01 degrees) revealed a change in oxidation state of Fe with increased fraction of Zinc interstitials, Zn-i and Oxygen vacancy, V-o defects through Photoelectron spectroscopy and Photoluminescence (PL) studies. The Raman and PL spectra have registered the inclusion of V-o-Zni complex defects also. An ideal position of E-2(Low) Raman mode justifies the effectual cationic substitution of Fe species. Inclusion of paramagnetic (PM) component is successfully substantiated through Bound Magnetic Polaron (BMP) model fitting. For x = 0.01, a residual PM component is ensured through temperature dependent magnetization, M(T) characteristics as well. A close fit of the Field cooled (FC) branch by the 3-D spin wave model (T = 99-300 K) points towards the intrinsic nature of ferromagnetism mediated by the effectual substitution of Fe2+ ions and the inclusion of BMPs. At lower temperature (T < 99 K), a good fit to the Curie-Weiss model (C-W) quantifies an estimated cluster size of the order of 10(-3), subtle enough to restrict the introduction of spin glass state, thereby justifying the suitability of these nanoparticles for spintronics applications. Excellent PM properties are achieved for x = 0.03 at T = 300 K. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.