Enhanced Magnetic Properties of In-Mn Codoped Plasmonic ZnO Nanoflowers: Evidence of Delocalized Charge Carrier Mediated Ferromagnetic Coupling

We report a detailed study of temperature and magnetic field dependence of the magnetization of free-standing colloidal Mn-doped and In-Mn codopedZnO nanoflower (NF) powders including their optical spectroscopic properties to explore the delocalized charge carrier (conduction band electron) mediated ferromagnetic coupling in dilute magnetically doped semiconductor (DMS), which could empower the next generation spin-based information technologies. In this present investigation, all samples are characterized by the hexagonal wurtzite (P63mc) crystal structure; though, the hexagonal shape of pure ZnO nanocrystals is transformed into the flower-like morphology with Mn doping and In-Mn codoping samples. The Zn interstitial defects, traced through the blue photoluminescence emissions, have been found to form bound magnetic polarons (BMPs) in presence of spin-↑ Mn2+ ions in Zn0.9Mn0.1O NFs. The overlapping of these BMPs typically leads to above room-temperature ferromagnetism in Zn0.9Mn0.1O NFs. Exclusively, the...