Magnetism of Undoped ZrO2 Nanoparticles Deposited by Plasma-Gas-Condensation Technology

The magnetic properties of undoped ZrO2 nanoparticles (NPs) deposited by plasma-gas-condensation technology were studied. The as-prepared ZrO2 NPs with controllable particle sizes (6-13 nm) presents tetragonal phase which was hardly acquired by traditional methods at room temperature. The as-deposited ZrO2 NPs were annealed at 300 to 1000 °C in air or mixed gas of Ar (95%) + H2 (5%) for 3 h, respectively. XRD results show that the phase of ZrO2 NPs gradually transformed from tetragonal to monoclinic with increasing the annealing temperature. The magnetic results of ZrO2 NPs under all annealing treatments were paramagnetic, which are different with the diamagnetic or ferromagnetic ones, also different from magnetic property changed after annealing in some other works.