Manganese-doped zirconia nanocrystals

In recent theoretical work, it was predicted that transition-metal-doped zirconia (ZrO₂) can be ferromagnetic at room temperature with a dependence on the metal dopant and its oxidation state and concentration. ^[1] For experimental verification of these predictions, manganese-doped ZrO₂ nanoparticles were synthesized. The synthesis was achieved by the benzyl alcohol route, which led to high-quality nanocrystals with uniform size and shape. The obtained particles present a homogeneous distribution of the magnetic ion. The crystallographic phase was studied by XRD, electron diffraction, and high-resolution TEM. The doping efficiency was determined at the macroscopic level by chemical analysis and at the nanoscale level by electron energy loss spectrometry. The local structure of the manganese ions in the ZrO₂ matrix was characterized by electron paramagnetic resonance. Finally, the magnetic properties of the obtained nanocrystals were investigated by susceptibility measurements.