Ferromagnetic ZnO nanoparticles prepared by pulsed laser deposition in liquid

Pulsed laser ablation (PLA) has recently been used to synthesize metal and ceramic nanostructures. The PLA method is highly advantageous because nanoparticle (NPs) synthesis is possible without organic binders or expensive equipment required to obtain high vacuum. In this letter we report on the synthesis and magnetic properties of ZnO nanoparticles by PLA of a solid ZnO target in water. The mean size of the ZnO NPs is ∼100 nm after dispersion. The ZnO NPs show clear characteristics of room temperature ferromagnetism. The saturation moment (Ms) of the ZnO NPs is almost unchanged with temperature, which suggests that the fundamental mechanism is different than the traditional double exchange model. So-called d0 magnetism has been invoked to explain the magnetic characteristics.

► Zinc oxide nanoparticles were prepared by pulsed laser ablation of a solid target in water.
► Mean size of the nanoparticles is ∼100 nm.
► Size of the particles is independent of the number of pulses on the solid target.
► Pure zinc oxide nanoparticles were ferromagnetic.