A free-standing magneto-fluorescent La1-xSrxMnO3@ZnO nanoparticle: Synthesis, properties and sharp Curie transition

A free-standing magneto-fluorescent La1-xSrxMnO3@ZnO multifunctional core-shell nanoparticle system with a sharp, tight phase transition from ferromagnetic to superparamagnetic states, was synthesized by a modified nanoemulsion process with poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The XRD and TEM/HRTEM show high crystallinity of the La1-xSrxMnO3@ZnO nanoparticles and an average particle size of similar to 22.2 nm. The measurements using UV-vis, PL, VSM and PPMS reveal that the nanoparticles exhibit well-behaved absorption bands and multiple visible fingerprint photoluminescent emissions in both aqueous and organic media, and superparamagnetic behavior at room temperature. Particularly, a tight, sharp phase transition from ferromagnetic to superparamagnetic states is observed in the La1-xSrxMnO3@ZnO nanoparticle system for the first time with a Curie temperature around room temperature. The results demonstrate that the multifunctional La1-xSrxMnO3@ZnO core-shell nanoparticles could be of interest for scientific studies and potential applications. (C) 2016 Elsevier B.V. All rights reserved.